diff --git a/src/ui/public/paginated_table/paginated_table.js b/src/ui/public/paginated_table/paginated_table.js
index 91947f9b060a..af6900584000 100644
--- a/src/ui/public/paginated_table/paginated_table.js
+++ b/src/ui/public/paginated_table/paginated_table.js
@@ -4,7 +4,7 @@ import paginatedTableTemplate from 'ui/paginated_table/paginated_table.html';
 uiModules
 .get('kibana')
 .directive('paginatedTable', function ($filter) {
-  var orderBy = $filter('orderBy');
+  let orderBy = $filter('orderBy');
 
   return {
     restrict: 'E',
@@ -19,14 +19,14 @@ uiModules
     },
     controllerAs: 'paginatedTable',
     controller: function ($scope) {
-      var self = this;
+      let self = this;
       self.sort = {
         columnIndex: null,
         direction: null
       };
 
       self.sortColumn = function (colIndex) {
-        var col = $scope.columns[colIndex];
+        let col = $scope.columns[colIndex];
 
         if (!col) return;
         if (col.sortable === false) return;
@@ -36,7 +36,7 @@ uiModules
         if (self.sort.columnIndex !== colIndex) {
           sortDirection = 'asc';
         } else {
-          var directions = {
+          let directions = {
             null: 'asc',
             'asc': 'desc',
             'desc': null
@@ -56,7 +56,7 @@ uiModules
         } else {
           // use generic sort handler
           self.sort.getter = function (row) {
-            var value = row[index];
+            let value = row[index];
             if (value && value.value != null) value = value.value;
             if (typeof value === 'boolean') value = value ? 0 : 1;
             return value;
@@ -75,7 +75,7 @@ uiModules
           return;
         }
 
-        var sort = self.sort;
+        let sort = self.sort;
         if (sort.direction == null) {
           $scope.sortedRows = $scope.rows.slice(0);
         } else {
diff --git a/src/ui/public/parse_query/lib/from_user.js b/src/ui/public/parse_query/lib/from_user.js
index c2eefd85c483..6aac1f93c0fe 100644
--- a/src/ui/public/parse_query/lib/from_user.js
+++ b/src/ui/public/parse_query/lib/from_user.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 import DecorateQueryProvider from 'ui/courier/data_source/_decorate_query';
 export default function GetQueryFromUser(es, Private) {
-  var decorateQuery = Private(DecorateQueryProvider);
+  let decorateQuery = Private(DecorateQueryProvider);
 
   /**
    * Take text from the user and make it into a query object
@@ -13,7 +13,7 @@ export default function GetQueryFromUser(es, Private) {
       return decorateQuery({query_string: {query: text}});
     }
 
-    var matchAll = getQueryStringQuery('*');
+    let matchAll = getQueryStringQuery('*');
 
     // If we get an empty object, treat it as a *
     if (_.isObject(text)) {
diff --git a/src/ui/public/parse_query/parse_query.js b/src/ui/public/parse_query/parse_query.js
index 8cae03fca433..148a2f962f79 100644
--- a/src/ui/public/parse_query/parse_query.js
+++ b/src/ui/public/parse_query/parse_query.js
@@ -4,7 +4,7 @@ import uiModules from 'ui/modules';
 uiModules
   .get('kibana')
   .directive('parseQuery', function (Private) {
-    var fromUser = Private(ParseQueryLibFromUserProvider);
+    let fromUser = Private(ParseQueryLibFromUserProvider);
 
     return {
       restrict: 'A',
@@ -13,7 +13,7 @@ uiModules
         'ngModel': '='
       },
       link: function ($scope, elem, attr, ngModel) {
-        var init = function () {
+        let init = function () {
           $scope.ngModel = fromUser($scope.ngModel);
         };
 
diff --git a/src/ui/public/persisted_state/persisted_state.js b/src/ui/public/persisted_state/persisted_state.js
index f31636b326b5..3975c20c24ea 100644
--- a/src/ui/public/persisted_state/persisted_state.js
+++ b/src/ui/public/persisted_state/persisted_state.js
@@ -5,7 +5,7 @@ import SimpleEmitter from 'ui/utils/simple_emitter';
 import EventsProvider from 'ui/events';
 
 export default function (Private) {
-  var Events = Private(EventsProvider);
+  let Events = Private(EventsProvider);
 
   function validateParent(parent, path) {
     if (path.length <= 0) {
@@ -17,7 +17,7 @@ export default function (Private) {
   }
 
   function validateValue(value) {
-    var msg = 'State value must be a plain object';
+    let msg = 'State value must be a plain object';
     if (!value) return;
     if (!_.isPlainObject(value)) throw new errors.PersistedStateError(msg);
   }
@@ -73,21 +73,21 @@ export default function (Private) {
   };
 
   PersistedState.prototype.set = function (key, value) {
-    var params = prepSetParams(key, value, this._path);
-    var val = this._set(params.key, params.value);
+    let params = prepSetParams(key, value, this._path);
+    let val = this._set(params.key, params.value);
     this.emit('set');
     return val;
   };
 
   PersistedState.prototype.setSilent = function (key, value) {
-    var params = prepSetParams(key, value, this._path);
+    let params = prepSetParams(key, value, this._path);
     return this._set(params.key, params.value, true);
   };
 
   PersistedState.prototype.reset = function (path) {
-    var keyPath = this._getIndex(path);
-    var origValue = _.get(this._defaultState, keyPath);
-    var currentValue = _.get(this._mergedState, keyPath);
+    let keyPath = this._getIndex(path);
+    let origValue = _.get(this._defaultState, keyPath);
+    let currentValue = _.get(this._mergedState, keyPath);
 
     if (_.isUndefined(origValue)) {
       this._cleanPath(path, this._mergedState);
@@ -108,7 +108,7 @@ export default function (Private) {
   };
 
   PersistedState.prototype.removeChild = function (path) {
-    var origValue = _.get(this._defaultState, this._getIndex(path));
+    let origValue = _.get(this._defaultState, this._getIndex(path));
 
     if (_.isUndefined(origValue)) {
       this.reset(path);
@@ -139,19 +139,19 @@ export default function (Private) {
   };
 
   PersistedState.prototype._getPartialIndex = function (key) {
-    var keyPath = this._getIndex(key);
+    let keyPath = this._getIndex(key);
     return keyPath.slice(this._path.length);
   };
 
   PersistedState.prototype._cleanPath = function (path, stateTree) {
-    var partialPath = this._getPartialIndex(path);
-    var remove = true;
+    let partialPath = this._getPartialIndex(path);
+    let remove = true;
 
     // recursively delete value tree, when no other keys exist
     while (partialPath.length > 0) {
-      var lastKey = partialPath.splice(partialPath.length - 1, 1)[0];
-      var statePath = this._path.concat(partialPath);
-      var stateVal = statePath.length > 0 ? _.get(stateTree, statePath) : stateTree;
+      let lastKey = partialPath.splice(partialPath.length - 1, 1)[0];
+      let statePath = this._path.concat(partialPath);
+      let stateVal = statePath.length > 0 ? _.get(stateTree, statePath) : stateTree;
 
       // if stateVal isn't an object, do nothing
       if (!_.isPlainObject(stateVal)) return;
@@ -162,13 +162,13 @@ export default function (Private) {
   };
 
   PersistedState.prototype._getDefault = function () {
-    var def = (this._hasPath()) ? undefined : {};
+    let def = (this._hasPath()) ? undefined : {};
     return (this._parent ? this.get() : def);
   };
 
   PersistedState.prototype._setPath = function (path) {
-    var isString = _.isString(path);
-    var isArray = _.isArray(path);
+    let isString = _.isString(path);
+    let isArray = _.isArray(path);
 
     if (!isString && !isArray) return [];
     return (isString) ? [this._getIndex(path)] : path;
@@ -196,11 +196,11 @@ export default function (Private) {
   };
 
   PersistedState.prototype._set = function (key, value, silent, initialChildState) {
-    var self = this;
-    var stateChanged = false;
-    var initialState = !this._initialized;
-    var keyPath = this._getIndex(key);
-    var hasKeyPath = keyPath.length > 0;
+    let self = this;
+    let stateChanged = false;
+    let initialState = !this._initialized;
+    let keyPath = this._getIndex(key);
+    let hasKeyPath = keyPath.length > 0;
 
     // if this is the initial state value, save value as the default
     if (initialState) {
@@ -226,7 +226,7 @@ export default function (Private) {
         }
       } else {
         // check for changes at path, emit an event when different
-        var curVal = hasKeyPath ? this.get(keyPath) : this._mergedState;
+        let curVal = hasKeyPath ? this.get(keyPath) : this._mergedState;
         stateChanged = !_.isEqual(curVal, value);
 
         if (!initialChildState) {
@@ -243,11 +243,11 @@ export default function (Private) {
     }
 
     // update the merged state value
-    var targetObj = this._mergedState || _.cloneDeep(this._defaultState);
-    var sourceObj = _.merge({}, this._defaultChildState, this._changedState);
+    let targetObj = this._mergedState || _.cloneDeep(this._defaultState);
+    let sourceObj = _.merge({}, this._defaultChildState, this._changedState);
 
     // handler arguments are (targetValue, sourceValue, key, target, source)
-    var mergeMethod = function (targetValue, sourceValue, mergeKey) {
+    let mergeMethod = function (targetValue, sourceValue, mergeKey) {
       // if not initial state, skip default merge method (ie. return value, see note below)
       if (!initialState && !initialChildState && _.isEqual(keyPath, self._getIndex(mergeKey))) {
         // use the sourceValue or fall back to targetValue
diff --git a/src/ui/public/private/private.js b/src/ui/public/private/private.js
index ead3fbbde6c3..4c371da82cc4 100644
--- a/src/ui/public/private/private.js
+++ b/src/ui/public/private/private.js
@@ -23,10 +23,10 @@ import uiModules from 'ui/modules';
  * ```js
  * define(function (require) {
  *   return function ServerHealthProvider(Private, Promise) {
- *     var ping = Private(require('ui/ping'));
+ *     let ping = Private(require('ui/ping'));
  *     return {
  *       check: Promise.method(function () {
- *         var attempts = 0;
+ *         let attempts = 0;
  *         return (function attempt() {
  *           attempts += 1;
  *           return ping.ping()
@@ -87,7 +87,7 @@ import uiModules from 'ui/modules';
  */
 
 
-var nextId = _.partial(_.uniqueId, 'privateProvider#');
+let nextId = _.partial(_.uniqueId, 'privateProvider#');
 
 function name(fn) {
   return fn.name || fn.toString().split('\n').shift();
@@ -95,11 +95,11 @@ function name(fn) {
 
 uiModules.get('kibana')
 .provider('Private', function () {
-  var provider = this;
+  let provider = this;
 
   // one cache/swaps per Provider
-  var cache = {};
-  var swaps = {};
+  let cache = {};
+  let swaps = {};
 
   // return the uniq id for this function
   function identify(fn) {
@@ -117,15 +117,15 @@ uiModules.get('kibana')
   };
 
   provider.swap = function (fn, prov) {
-    var id = identify(fn);
+    let id = identify(fn);
     swaps[id] = prov;
   };
 
   provider.$get = ['$injector', function PrivateFactory($injector) {
 
     // prevent circular deps by tracking where we came from
-    var privPath = [];
-    var pathToString = function () {
+    let privPath = [];
+    let pathToString = function () {
       return privPath.map(name).join(' -> ');
     };
 
@@ -140,8 +140,8 @@ uiModules.get('kibana')
 
       privPath.push(prov);
 
-      var context = {};
-      var instance = $injector.invoke(prov, context, locals);
+      let context = {};
+      let instance = $injector.invoke(prov, context, locals);
       if (!_.isObject(instance)) instance = context;
 
       privPath.pop();
@@ -167,7 +167,7 @@ uiModules.get('kibana')
 
     // main api, get the appropriate instance for a provider
     function Private(prov) {
-      var id = identify(prov);
+      let id = identify(prov);
       let $delegateId;
       let $delegateProv;
 
diff --git a/src/ui/public/promises/promises.js b/src/ui/public/promises/promises.js
index af9f21212d6a..a2d1ef5249c2 100644
--- a/src/ui/public/promises/promises.js
+++ b/src/ui/public/promises/promises.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 import uiModules from 'ui/modules';
 
-var module = uiModules.get('kibana');
+let module = uiModules.get('kibana');
 
 // Provides a tiny subset of the excelent API from
 // bluebird, reimplemented using the $q service
@@ -9,7 +9,7 @@ module.service('Promise', function ($q, $timeout) {
   function Promise(fn) {
     if (typeof this === 'undefined') throw new Error('Promise constructor must be called with "new"');
 
-    var defer = $q.defer();
+    let defer = $q.defer();
     try {
       fn(defer.resolve, defer.reject);
     } catch (e) {
@@ -20,12 +20,12 @@ module.service('Promise', function ($q, $timeout) {
 
   Promise.all = Promise.props = $q.all;
   Promise.resolve = function (val) {
-    var defer = $q.defer();
+    let defer = $q.defer();
     defer.resolve(val);
     return defer.promise;
   };
   Promise.reject = function (reason) {
-    var defer = $q.defer();
+    let defer = $q.defer();
     defer.reject(reason);
     return defer.promise;
   };
@@ -36,7 +36,7 @@ module.service('Promise', function ($q, $timeout) {
   };
   Promise.method = function (fn) {
     return function () {
-      var args = Array.prototype.slice.call(arguments);
+      let args = Array.prototype.slice.call(arguments);
       return Promise.try(fn, args, this);
     };
   };
@@ -64,7 +64,7 @@ module.service('Promise', function ($q, $timeout) {
     return obj && typeof obj.then === 'function';
   };
   Promise.halt = _.once(function () {
-    var promise = new Promise();
+    let promise = new Promise();
     promise.then = _.constant(promise);
     promise.catch = _.constant(promise);
     return promise;
@@ -155,7 +155,7 @@ module.factory('PromiseEmitter', function (Promise) {
    * @return {Promise}
    */
   function PromiseEmitter(fn, handler) {
-    var prom = new Promise(fn);
+    let prom = new Promise(fn);
 
     if (!handler) return prom;
 
diff --git a/src/ui/public/reflow_watcher/reflow_watcher.js b/src/ui/public/reflow_watcher/reflow_watcher.js
index 6a6bcb4aee1e..2592cc9e4bc1 100644
--- a/src/ui/public/reflow_watcher/reflow_watcher.js
+++ b/src/ui/public/reflow_watcher/reflow_watcher.js
@@ -4,12 +4,12 @@ import _ from 'lodash';
 import EventsProvider from 'ui/events';
 export default function ReflowWatcherService(Private, $rootScope, $http) {
 
-  var EventEmitter = Private(EventsProvider);
-  var $body = $(document.body);
-  var $window = $(window);
+  let EventEmitter = Private(EventsProvider);
+  let $body = $(document.body);
+  let $window = $(window);
 
-  var MOUSE_EVENTS = 'mouseup';
-  var WINDOW_EVENTS = 'resize';
+  let MOUSE_EVENTS = 'mouseup';
+  let WINDOW_EVENTS = 'resize';
 
   _.class(ReflowWatcher).inherits(EventEmitter);
   /**
diff --git a/src/ui/public/registry/_registry.js b/src/ui/public/registry/_registry.js
index 94c2bf6a3a96..396ad08237ed 100644
--- a/src/ui/public/registry/_registry.js
+++ b/src/ui/public/registry/_registry.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 import IndexedArray from 'ui/indexed_array';
 import RegistryVisTypesProvider from 'ui/registry/vis_types';
-var notPropsOptNames = IndexedArray.OPT_NAMES.concat('constructor');
+let notPropsOptNames = IndexedArray.OPT_NAMES.concat('constructor');
 
 /**
  * Create a registry, which is just a Private module provider.
@@ -16,7 +16,7 @@ var notPropsOptNames = IndexedArray.OPT_NAMES.concat('constructor');
  *
  * + register a module
  * ```js
- * var registry = require('ui/registry/vis_types');
+ * let registry = require('ui/registry/vis_types');
  * registry.add(function InjectablePrivateModule($http, Promise) {
  *   ...
  * })
@@ -24,7 +24,7 @@ var notPropsOptNames = IndexedArray.OPT_NAMES.concat('constructor');
  *
  * + get all registered modules
  * ```js
- * var visTypes = Private(RegistryVisTypesProvider);
+ * let visTypes = Private(RegistryVisTypesProvider);
  * ```
  *
  *
@@ -49,10 +49,10 @@ var notPropsOptNames = IndexedArray.OPT_NAMES.concat('constructor');
 export default function createRegistry(spec) {
   spec = spec || {};
 
-  var constructor = _.has(spec, 'constructor') && spec.constructor;
-  var iaOpts = _.defaults(_.pick(spec, IndexedArray.OPT_NAMES), { index: ['name'] });
-  var props = _.omit(spec, notPropsOptNames);
-  var providers = [];
+  let constructor = _.has(spec, 'constructor') && spec.constructor;
+  let iaOpts = _.defaults(_.pick(spec, IndexedArray.OPT_NAMES), { index: ['name'] });
+  let props = _.omit(spec, notPropsOptNames);
+  let providers = [];
 
   /**
    * This is the Private module that will be instanciated by
@@ -62,10 +62,10 @@ export default function createRegistry(spec) {
    *                          that were registered, the registry spec
    *                          defines how things will be indexed.
    */
-  var registry = function (Private, $injector) {
+  let registry = function (Private, $injector) {
     // index all of the modules
     iaOpts.initialSet = providers.map(Private);
-    var modules = new IndexedArray(iaOpts);
+    let modules = new IndexedArray(iaOpts);
 
     // mixin other props
     _.assign(modules, props);
diff --git a/src/ui/public/registry/field_formats.js b/src/ui/public/registry/field_formats.js
index 7b376f2b8a4d..941353001b71 100644
--- a/src/ui/public/registry/field_formats.js
+++ b/src/ui/public/registry/field_formats.js
@@ -7,7 +7,7 @@ export default uiRegistry({
   group: ['fieldType'],
 
   constructor: function (config, $rootScope) {
-    var self = this;
+    let self = this;
     let defaultMap;
 
     function init() {
@@ -56,7 +56,7 @@ export default uiRegistry({
      * @return {FieldFormat}
      */
     self.getInstance = _.memoize(function (formatId) {
-      var FieldFormat = self.byId[formatId];
+      let FieldFormat = self.byId[formatId];
       return new FieldFormat();
     });
 
@@ -67,8 +67,8 @@ export default uiRegistry({
      * @return {FieldFormat}
      */
     self.getDefaultInstance = _.memoize(function (fieldType) {
-      var conf = self.getDefaultConfig(fieldType);
-      var FieldFormat = self.byId[conf.id];
+      let conf = self.getDefaultConfig(fieldType);
+      let FieldFormat = self.byId[conf.id];
       return new FieldFormat(conf.params);
     });
 
diff --git a/src/ui/public/routes/route_manager.js b/src/ui/public/routes/route_manager.js
index 01ec0a6aa644..832990ba6de6 100644
--- a/src/ui/public/routes/route_manager.js
+++ b/src/ui/public/routes/route_manager.js
@@ -4,16 +4,16 @@ import wrapRouteWithPrep from './wrap_route_with_prep';
 import RouteSetupManager from './route_setup_manager';
 
 function RouteManager() {
-  var self = this;
-  var setup = new RouteSetupManager();
-  var when = [];
-  var defaults = [];
+  let self = this;
+  let setup = new RouteSetupManager();
+  let when = [];
+  let defaults = [];
   let otherwise;
 
   self.config = function ($routeProvider) {
     when.forEach(function (args) {
-      var path = args[0];
-      var route = args[1] || {};
+      let path = args[0];
+      let route = args[1] || {};
 
       // merge in any defaults
       defaults.forEach(function (args) {
diff --git a/src/ui/public/routes/route_setup_manager.js b/src/ui/public/routes/route_setup_manager.js
index 28e486d80fc8..1cb89fe45645 100644
--- a/src/ui/public/routes/route_setup_manager.js
+++ b/src/ui/public/routes/route_setup_manager.js
@@ -66,7 +66,7 @@ module.exports = class RouteSetupManager {
     )
     .then(() => {
       // wait for the queue to fill up, then do all the work
-      var defer = Promise.defer();
+      let defer = Promise.defer();
       userWork.resolveWhenFull(defer);
 
       return defer.promise.then(() => Promise.all(userWork.doWork()));
diff --git a/src/ui/public/routes/routes.js b/src/ui/public/routes/routes.js
index 7bdafc6b6930..cbb9878df7a1 100644
--- a/src/ui/public/routes/routes.js
+++ b/src/ui/public/routes/routes.js
@@ -1,7 +1,7 @@
 import RouteManager from './route_manager';
 import 'angular-route/angular-route';
 import uiModules from 'ui/modules';
-var defaultRouteManager = new RouteManager();
+let defaultRouteManager = new RouteManager();
 
 module.exports = {
   ...defaultRouteManager,
diff --git a/src/ui/public/routes/work_queue.js b/src/ui/public/routes/work_queue.js
index eb2aa086588f..40f429432782 100644
--- a/src/ui/public/routes/work_queue.js
+++ b/src/ui/public/routes/work_queue.js
@@ -1,10 +1,10 @@
 import _ from 'lodash';
 
 function WorkQueue() {
-  var q = this;
+  let q = this;
 
-  var work = [];
-  var fullDefers = [];
+  let work = [];
+  let fullDefers = [];
 
   q.limit = 0;
   Object.defineProperty(q, 'length', {
@@ -13,13 +13,13 @@ function WorkQueue() {
     }
   });
 
-  var resolve = function (defers) {
+  let resolve = function (defers) {
     return defers.splice(0).map(function (defer) {
       return defer.resolve();
     });
   };
 
-  var checkIfFull = function () {
+  let checkIfFull = function () {
     if (work.length >= q.limit && fullDefers.length) {
       resolve(fullDefers);
     }
@@ -31,7 +31,7 @@ function WorkQueue() {
   };
 
   q.doWork = function () {
-    var resps = resolve(work);
+    let resps = resolve(work);
     checkIfFull();
     return resps;
   };
diff --git a/src/ui/public/routes/wrap_route_with_prep.js b/src/ui/public/routes/wrap_route_with_prep.js
index e5156eb4df2c..5c4b98a82d0a 100644
--- a/src/ui/public/routes/wrap_route_with_prep.js
+++ b/src/ui/public/routes/wrap_route_with_prep.js
@@ -7,11 +7,11 @@ import errors from 'ui/errors';
 function wrapRouteWithPrep(route, setup) {
   if (!route.resolve && route.redirectTo) return;
 
-  var userWork = new WorkQueue();
+  let userWork = new WorkQueue();
   // the point at which we will consider the queue "full"
   userWork.limit = _.keys(route.resolve).length;
 
-  var resolve = {
+  let resolve = {
     __prep__: function ($injector) {
       return $injector.invoke(setup.doWork, setup, { userWork });
     }
@@ -21,7 +21,7 @@ function wrapRouteWithPrep(route, setup) {
   // prep is complete
   _.forOwn(route.resolve || {}, function (expr, name) {
     resolve[name] = function ($injector, Promise) {
-      var defer = Promise.defer();
+      let defer = Promise.defer();
       userWork.push(defer);
       return defer.promise.then(function () {
         return $injector[angular.isString(expr) ? 'get' : 'invoke'](expr);
diff --git a/src/ui/public/stack_trace_mapper/set_error_stack.js b/src/ui/public/stack_trace_mapper/set_error_stack.js
index 8ce562f0fbd8..ff6f5b783845 100644
--- a/src/ui/public/stack_trace_mapper/set_error_stack.js
+++ b/src/ui/public/stack_trace_mapper/set_error_stack.js
@@ -1,6 +1,6 @@
 import _ from 'lodash';
 
-var err = new Error();
+let err = new Error();
 try { setByAssignment(err, 'john'); } catch (e) {} // eslint-disable-line
 
 // err.stack is not always writeable, so we
@@ -13,7 +13,7 @@ if (err.stack === 'john') module.exports = setByAssignment;
 else module.exports = setByShadowing;
 
 function setByShadowing(err, stack) {
-  var props = _.mapValues(err, function (val) {
+  let props = _.mapValues(err, function (val) {
     return {
       enumerable: true,
       value: val
diff --git a/src/ui/public/stack_trace_mapper/stack_line_format.js b/src/ui/public/stack_trace_mapper/stack_line_format.js
index e1486aee635e..7d4c2ebe476c 100644
--- a/src/ui/public/stack_trace_mapper/stack_line_format.js
+++ b/src/ui/public/stack_trace_mapper/stack_line_format.js
@@ -1,6 +1,6 @@
 import _ from 'lodash';
 
-var opts = [
+let opts = [
   /@((?:[!#$&-;=?-\[\]_a-z~]|%[0-9a-f]{2})+\.js)\:(\d+)(?:\:(\d+)|())/ig,
   /(?: \(|at )((?:[!#$&-;=?-\[\]_a-z~]|%[0-9a-f]{2})+\.js)\:(\d+)(?:\:(\d+)|())/ig
 ];
@@ -8,7 +8,7 @@ var opts = [
 let sample;
 try { throw new Error('msg'); } catch (e) { sample = e.stack; }
 
-var format = _.find(opts, function (format) {
+let format = _.find(opts, function (format) {
   return format.test(sample);
 });
 
diff --git a/src/ui/public/stack_trace_mapper/stack_trace_mapper.js b/src/ui/public/stack_trace_mapper/stack_trace_mapper.js
index fbf8fa05f29a..85b436618433 100644
--- a/src/ui/public/stack_trace_mapper/stack_trace_mapper.js
+++ b/src/ui/public/stack_trace_mapper/stack_trace_mapper.js
@@ -22,7 +22,7 @@ StackTraceMapper.prototype.init = function (mapUrls) {
 StackTraceMapper.prototype.mapError = function (err) {
   if (!stackLineFormat || !err.stack) return err;
 
-  var stack = err.stack.replace(stackLineFormat, this.mapLine);
+  let stack = err.stack.replace(stackLineFormat, this.mapLine);
   return setErrorStack(err, stack);
 };
 
@@ -39,10 +39,10 @@ StackTraceMapper.prototype.getMapFor = function (url) {
 StackTraceMapper.prototype.loadMaps = function (mapUrls) {
   mapUrls = _.clone(mapUrls || {});
 
-  var maps = this.maps;
+  let maps = this.maps;
 
   $('script[src][src-map]').each(function () {
-    var $el = $(this);
+    let $el = $(this);
     mapUrls[$el.attr('src')] = $el.attr('src-map');
   });
 
diff --git a/src/ui/public/stack_trace_mapper/translate_stack_line.js b/src/ui/public/stack_trace_mapper/translate_stack_line.js
index 103ef5d98964..f19f64cfe618 100644
--- a/src/ui/public/stack_trace_mapper/translate_stack_line.js
+++ b/src/ui/public/stack_trace_mapper/translate_stack_line.js
@@ -3,17 +3,17 @@ import _ from 'lodash';
 module.exports = function (map, match, filename, line, col) {
   if (!map) return match;
 
-  var position = {
+  let position = {
     line: parseFloat(line) || 0,
     column: parseFloat(col) || 0
   };
 
-  var srcPosition = map.smc.originalPositionFor(position);
+  let srcPosition = map.smc.originalPositionFor(position);
   if (!srcPosition || !srcPosition.source) return match;
 
-  var srcFilename = srcPosition.source;
-  var srcLine = srcPosition.line;
-  var srcCol = srcPosition.column;
+  let srcFilename = srcPosition.source;
+  let srcLine = srcPosition.line;
+  let srcCol = srcPosition.column;
 
   if (srcCol === 0 && position.column) {
     // TODO: teach sourcemaps correct column
@@ -26,10 +26,10 @@ module.exports = function (map, match, filename, line, col) {
   // fold the components into the original match, so that supporting
   // characters (parens, periods, etc) from the format are kept, and so
   // we don't accidentally replace the wrong part we use splitting and consumption
-  var resp = '';
-  var remainingResp = match;
-  var fold = function (replace, replacement) {
-    var wrappingContent = remainingResp.split(replace);
+  let resp = '';
+  let remainingResp = match;
+  let fold = function (replace, replacement) {
+    let wrappingContent = remainingResp.split(replace);
     resp += wrappingContent.shift() + replacement;
     remainingResp = wrappingContent.join(replace);
   };
diff --git a/src/ui/public/state_management/_state_sync.js b/src/ui/public/state_management/_state_sync.js
index d94b5f6ffd72..61dc9011f76a 100644
--- a/src/ui/public/state_management/_state_sync.js
+++ b/src/ui/public/state_management/_state_sync.js
@@ -7,8 +7,8 @@ import rison from 'ui/utils/rison';
 export default function ($location) {
   // feed in some of the private state from globalState
   return function (globalState, updateListeners, app) {
-    var getAppStash = function (search) {
-      var appStash = search._a && rison.decode(search._a);
+    let getAppStash = function (search) {
+      let appStash = search._a && rison.decode(search._a);
       if (app.current) {
         // Apply the defaults to appStash
         appStash = _.defaults(appStash || {}, app.defaults);
@@ -16,20 +16,20 @@ export default function ($location) {
       return appStash;
     };
 
-    var diffTrans = function (trans) {
-      var obj = trans[0];
-      var update = trans[1];
+    let diffTrans = function (trans) {
+      let obj = trans[0];
+      let update = trans[1];
 
-      var diff = {};
+      let diff = {};
 
       // the keys that are currently set on obj, excluding methods
-      var objKeys = Object.keys(obj).filter(function (key) {
+      let objKeys = Object.keys(obj).filter(function (key) {
         return typeof obj[key] !== 'function';
       });
 
       if (update) {
         // the keys obj should have after applying the update
-        var updateKeys = diff.keys = Object.keys(update).filter(function (key) {
+        let updateKeys = diff.keys = Object.keys(update).filter(function (key) {
           return typeof update[key] !== 'function';
         });
 
@@ -52,8 +52,8 @@ export default function ($location) {
       return diff;
     };
 
-    var notify = function (trans, diff) {
-      var listeners = null;
+    let notify = function (trans, diff) {
+      let listeners = null;
 
       if (trans[0] === app.current) {
         listeners = app.listeners;
@@ -66,11 +66,11 @@ export default function ($location) {
       });
     };
 
-    var applyDiff = function (trans, diff) {
+    let applyDiff = function (trans, diff) {
       if (!diff.all.length) return;
 
-      var obj = trans[0];
-      var update = trans[1];
+      let obj = trans[0];
+      let update = trans[1];
 
       diff.remove.forEach(function (key) {
         delete obj[key];
@@ -81,13 +81,13 @@ export default function ($location) {
       });
     };
 
-    var syncTrans = function (trans, forceNotify) {
+    let syncTrans = function (trans, forceNotify) {
       // obj that will be modified by update(trans[1])
       // if it is empty, we can skip it all
-      var skipWrite = !trans[0];
+      let skipWrite = !trans[0];
       trans[0] = trans[0] || {};
 
-      var diff = diffTrans(trans);
+      let diff = diffTrans(trans);
       if (!skipWrite && (forceNotify || diff.all.length)) {
         applyDiff(trans, diff);
         notify(trans, diff);
@@ -98,17 +98,17 @@ export default function ($location) {
     return {
       // sync by pushing to the url
       push: function (forceNotify) {
-        var search = $location.search();
+        let search = $location.search();
 
-        var appStash = getAppStash(search) || {};
-        var globalStash = search._g ? rison.decode(search._g) : {};
+        let appStash = getAppStash(search) || {};
+        let globalStash = search._g ? rison.decode(search._g) : {};
 
-        var res = _.mapValues({
+        let res = _.mapValues({
           app: [appStash, app.current],
           global: [globalStash, globalState]
         }, function (trans, key) {
-          var diff = syncTrans(trans, forceNotify);
-          var urlKey = '_' + key.charAt(0);
+          let diff = syncTrans(trans, forceNotify);
+          let urlKey = '_' + key.charAt(0);
           if (diff.keys.length === 0) {
             delete search[urlKey];
           } else {
@@ -122,10 +122,10 @@ export default function ($location) {
       },
       // sync by pulling from the url
       pull: function (forceNotify) {
-        var search = $location.search();
+        let search = $location.search();
 
-        var appStash = getAppStash(search);
-        var globalStash = search._g && rison.decode(search._g);
+        let appStash = getAppStash(search);
+        let globalStash = search._g && rison.decode(search._g);
 
         return _.mapValues({
           app: [app.current, appStash],
diff --git a/src/ui/public/state_management/app_state.js b/src/ui/public/state_management/app_state.js
index 5f20cacef96a..8cb3320bf482 100644
--- a/src/ui/public/state_management/app_state.js
+++ b/src/ui/public/state_management/app_state.js
@@ -2,11 +2,11 @@ import _ from 'lodash';
 import modules from 'ui/modules';
 import StateManagementStateProvider from 'ui/state_management/state';
 import PersistedStatePersistedStateProvider from 'ui/persisted_state/persisted_state';
-var urlParam = '_a';
+let urlParam = '_a';
 
 function AppStateProvider(Private, $rootScope, getAppState) {
-  var State = Private(StateManagementStateProvider);
-  var PersistedState = Private(PersistedStatePersistedStateProvider);
+  let State = Private(StateManagementStateProvider);
+  let PersistedState = Private(PersistedStatePersistedStateProvider);
   let persistedStates;
   let eventUnsubscribers;
 
@@ -30,31 +30,31 @@ function AppStateProvider(Private, $rootScope, getAppState) {
 
   AppState.prototype.makeStateful = function (prop) {
     if (persistedStates[prop]) return persistedStates[prop];
-    var self = this;
+    let self = this;
 
     // set up the ui state
     persistedStates[prop] = new PersistedState();
 
     // update the app state when the stateful instance changes
-    var updateOnChange = function () {
-      var replaceState = false; // TODO: debouncing logic
+    let updateOnChange = function () {
+      let replaceState = false; // TODO: debouncing logic
 
       self[prop] = persistedStates[prop].getChanges();
       self.save(replaceState);
     };
-    var handlerOnChange = (method) => persistedStates[prop][method]('change', updateOnChange);
+    let handlerOnChange = (method) => persistedStates[prop][method]('change', updateOnChange);
     handlerOnChange('on');
     eventUnsubscribers.push(() => handlerOnChange('off'));
 
     // update the stateful object when the app state changes
-    var persistOnChange = function (changes) {
+    let persistOnChange = function (changes) {
       if (!changes) return;
 
       if (changes.indexOf(prop) !== -1) {
         persistedStates[prop].set(self[prop]);
       }
     };
-    var handlePersist = (method) => this[method]('fetch_with_changes', persistOnChange);
+    let handlePersist = (method) => this[method]('fetch_with_changes', persistOnChange);
     handlePersist('on');
     eventUnsubscribers.push(() => handlePersist('off'));
 
@@ -80,7 +80,7 @@ modules.get('kibana/global_state')
 
   // Checks to see if the appState might already exist, even if it hasn't been newed up
   get.previouslyStored = function () {
-    var search = $location.search();
+    let search = $location.search();
     return search[urlParam] ? true : false;
   };
 
diff --git a/src/ui/public/state_management/global_state.js b/src/ui/public/state_management/global_state.js
index f76f93a51de0..fcc3d202b66d 100644
--- a/src/ui/public/state_management/global_state.js
+++ b/src/ui/public/state_management/global_state.js
@@ -5,10 +5,10 @@ import rison from 'ui/utils/rison';
 import StateManagementStateProvider from 'ui/state_management/state';
 import uiModules from 'ui/modules';
 
-var module = uiModules.get('kibana/global_state');
+let module = uiModules.get('kibana/global_state');
 
 module.service('globalState', function (Private, $rootScope, $location) {
-  var State = Private(StateManagementStateProvider);
+  let State = Private(StateManagementStateProvider);
 
   _.class(GlobalState).inherits(State);
   function GlobalState(defaults) {
diff --git a/src/ui/public/state_management/state.js b/src/ui/public/state_management/state.js
index dfc0f8c62b7e..6fa8c1f3356b 100644
--- a/src/ui/public/state_management/state.js
+++ b/src/ui/public/state_management/state.js
@@ -7,13 +7,13 @@ import Notifier from 'ui/notify/notifier';
 
 
 export default function StateProvider(Private, $rootScope, $location) {
-  var Events = Private(EventsProvider);
+  let Events = Private(EventsProvider);
 
   _.class(State).inherits(Events);
   function State(urlParam, defaults) {
     State.Super.call(this);
 
-    var self = this;
+    let self = this;
     self.setDefaults(defaults);
     self._urlParam = urlParam || '_s';
 
@@ -40,11 +40,11 @@ export default function StateProvider(Private, $rootScope, $location) {
   }
 
   State.prototype._readFromURL = function () {
-    var search = $location.search();
+    let search = $location.search();
     try {
       return search[this._urlParam] ? rison.decode(search[this._urlParam]) : null;
     } catch (e) {
-      var notify = new Notifier();
+      let notify = new Notifier();
       notify.error('Unable to parse URL');
       search[this._urlParam] = rison.encode(this._defaults);
       $location.search(search).replace();
@@ -57,7 +57,7 @@ export default function StateProvider(Private, $rootScope, $location) {
    * @returns {void}
    */
   State.prototype.fetch = function () {
-    var stash = this._readFromURL();
+    let stash = this._readFromURL();
 
     // nothing to read from the url? save if ordered to persist
     if (stash === null) {
@@ -70,7 +70,7 @@ export default function StateProvider(Private, $rootScope, $location) {
 
     _.defaults(stash, this._defaults);
     // apply diff to state from stash, will change state in place via side effect
-    var diffResults = applyDiff(this, stash);
+    let diffResults = applyDiff(this, stash);
 
     if (diffResults.keys.length) {
       this.emit('fetch_with_changes', diffResults.keys);
@@ -82,8 +82,8 @@ export default function StateProvider(Private, $rootScope, $location) {
    * @returns {void}
    */
   State.prototype.save = function (replace) {
-    var stash = this._readFromURL();
-    var state = this.toObject();
+    let stash = this._readFromURL();
+    let state = this.toObject();
     replace = replace || false;
 
     if (!stash) {
@@ -93,14 +93,14 @@ export default function StateProvider(Private, $rootScope, $location) {
 
     _.defaults(state, this._defaults);
     // apply diff to state from stash, will change state in place via side effect
-    var diffResults = applyDiff(stash, state);
+    let diffResults = applyDiff(stash, state);
 
     if (diffResults.keys.length) {
       this.emit('save_with_changes', diffResults.keys);
     }
 
     // persist the state in the URL
-    var search = $location.search();
+    let search = $location.search();
     search[this._urlParam] = this.toRISON();
     if (replace) {
       $location.search(search).replace();
@@ -125,7 +125,7 @@ export default function StateProvider(Private, $rootScope, $location) {
   State.prototype.reset = function () {
     // apply diff to _attributes from defaults, this is side effecting so
     // it will change the state in place.
-    var diffResults = applyDiff(this, this._defaults);
+    let diffResults = applyDiff(this, this._defaults);
     if (diffResults.keys.length) {
       this.emit('reset_with_changes', diffResults.keys);
     }
diff --git a/src/ui/public/storage/storage.js b/src/ui/public/storage/storage.js
index a5c3ad10aeed..aa043158724b 100644
--- a/src/ui/public/storage/storage.js
+++ b/src/ui/public/storage/storage.js
@@ -2,7 +2,7 @@ import modules from 'ui/modules';
 import angular from 'angular';
 
 function Storage(store) {
-  var self = this;
+  let self = this;
   self.store = store;
 
   self.get = function (key) {
@@ -30,7 +30,7 @@ function Storage(store) {
   };
 }
 
-var createService = function (type) {
+let createService = function (type) {
   return function ($window) {
     return new Storage($window[type]);
   };
diff --git a/src/ui/public/stringify/types/_numeral.js b/src/ui/public/stringify/types/_numeral.js
index 2f448010caa2..ee55f155b434 100644
--- a/src/ui/public/stringify/types/_numeral.js
+++ b/src/ui/public/stringify/types/_numeral.js
@@ -3,9 +3,9 @@ import 'ui/field_format_editor/numeral/numeral';
 import IndexPatternsFieldFormatProvider from 'ui/index_patterns/_field_format/field_format';
 import BoundToConfigObjProvider from 'ui/bound_to_config_obj';
 export default function AbstractNumeralFormatProvider(Private) {
-  var FieldFormat = Private(IndexPatternsFieldFormatProvider);
-  var BoundToConfigObj = Private(BoundToConfigObjProvider);
-  var numeral = require('numeral')();
+  let FieldFormat = Private(IndexPatternsFieldFormatProvider);
+  let BoundToConfigObj = Private(BoundToConfigObjProvider);
+  let numeral = require('numeral')();
 
   _.class(Numeral).inherits(FieldFormat);
   function Numeral(params) {
diff --git a/src/ui/public/stringify/types/bytes.js b/src/ui/public/stringify/types/bytes.js
index d1fdcaf271ea..88e72823a4a4 100644
--- a/src/ui/public/stringify/types/bytes.js
+++ b/src/ui/public/stringify/types/bytes.js
@@ -1,7 +1,7 @@
 import StringifyTypesNumeralProvider from 'ui/stringify/types/_numeral';
 
 export default function BytesFormatProvider(Private) {
-  var Numeral = Private(StringifyTypesNumeralProvider);
+  let Numeral = Private(StringifyTypesNumeralProvider);
   return Numeral.factory({
     id: 'bytes',
     title: 'Bytes',
diff --git a/src/ui/public/stringify/types/date.js b/src/ui/public/stringify/types/date.js
index 4140c55d4d0f..d88ff3ed4d91 100644
--- a/src/ui/public/stringify/types/date.js
+++ b/src/ui/public/stringify/types/date.js
@@ -5,8 +5,8 @@ import IndexPatternsFieldFormatProvider from 'ui/index_patterns/_field_format/fi
 import BoundToConfigObjProvider from 'ui/bound_to_config_obj';
 import dateTemplate from 'ui/stringify/editors/date.html';
 export default function DateTimeFormatProvider(Private) {
-  var FieldFormat = Private(IndexPatternsFieldFormatProvider);
-  var BoundToConfigObj = Private(BoundToConfigObjProvider);
+  let FieldFormat = Private(IndexPatternsFieldFormatProvider);
+  let BoundToConfigObj = Private(BoundToConfigObjProvider);
 
 
   _.class(DateTime).inherits(FieldFormat);
@@ -27,7 +27,7 @@ export default function DateTimeFormatProvider(Private) {
     template: dateTemplate,
     controllerAs: 'cntrl',
     controller: function ($interval, $scope) {
-      var self = this;
+      let self = this;
       self.sampleInputs = [
         Date.now(),
         +moment().startOf('year'),
@@ -43,11 +43,11 @@ export default function DateTimeFormatProvider(Private) {
   DateTime.prototype._convert = function (val) {
     // don't give away our ref to converter so
     // we can hot-swap when config changes
-    var pattern = this.param('pattern');
-    var timezone = this.param('timezone');
+    let pattern = this.param('pattern');
+    let timezone = this.param('timezone');
 
-    var timezoneChanged = this._timeZone !== timezone;
-    var datePatternChanged = this._memoizedPattern !== pattern;
+    let timezoneChanged = this._timeZone !== timezone;
+    let datePatternChanged = this._memoizedPattern !== pattern;
     if (timezoneChanged || datePatternChanged) {
       this._timeZone = timezone;
       this._memoizedPattern = pattern;
diff --git a/src/ui/public/stringify/types/ip.js b/src/ui/public/stringify/types/ip.js
index 877bd1f464dc..b80c1951bad5 100644
--- a/src/ui/public/stringify/types/ip.js
+++ b/src/ui/public/stringify/types/ip.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 import IndexPatternsFieldFormatProvider from 'ui/index_patterns/_field_format/field_format';
 export default function IpFormatProvider(Private) {
-  var FieldFormat = Private(IndexPatternsFieldFormatProvider);
+  let FieldFormat = Private(IndexPatternsFieldFormatProvider);
 
   _.class(Ip).inherits(FieldFormat);
   function Ip(params) {
diff --git a/src/ui/public/stringify/types/number.js b/src/ui/public/stringify/types/number.js
index 7ffd611b4137..e9d12b1d241f 100644
--- a/src/ui/public/stringify/types/number.js
+++ b/src/ui/public/stringify/types/number.js
@@ -1,7 +1,7 @@
 import StringifyTypesNumeralProvider from 'ui/stringify/types/_numeral';
 
 export default function NumberFormatProvider(Private) {
-  var Numeral = Private(StringifyTypesNumeralProvider);
+  let Numeral = Private(StringifyTypesNumeralProvider);
   return Numeral.factory({
     id: 'number',
     title: 'Number',
diff --git a/src/ui/public/stringify/types/percent.js b/src/ui/public/stringify/types/percent.js
index 02a8be502f6d..f309604ef0f0 100644
--- a/src/ui/public/stringify/types/percent.js
+++ b/src/ui/public/stringify/types/percent.js
@@ -2,8 +2,8 @@ import _ from 'lodash';
 import BoundToConfigObjProvider from 'ui/bound_to_config_obj';
 import StringifyTypesNumeralProvider from 'ui/stringify/types/_numeral';
 export default function PercentFormatProvider(Private) {
-  var BoundToConfigObj = Private(BoundToConfigObjProvider);
-  var Numeral = Private(StringifyTypesNumeralProvider);
+  let BoundToConfigObj = Private(BoundToConfigObjProvider);
+  let Numeral = Private(StringifyTypesNumeralProvider);
 
   return Numeral.factory({
     id: 'percent',
diff --git a/src/ui/public/stringify/types/source.js b/src/ui/public/stringify/types/source.js
index b4c9473921e9..9662bfebef4e 100644
--- a/src/ui/public/stringify/types/source.js
+++ b/src/ui/public/stringify/types/source.js
@@ -3,8 +3,8 @@ import noWhiteSpace from 'ui/utils/no_white_space';
 import angular from 'angular';
 import IndexPatternsFieldFormatProvider from 'ui/index_patterns/_field_format/field_format';
 export default function _SourceFormatProvider(Private, shortDotsFilter) {
-  var FieldFormat = Private(IndexPatternsFieldFormatProvider);
-  var template = _.template(noWhiteSpace(require('ui/stringify/types/_source.html')));
+  let FieldFormat = Private(IndexPatternsFieldFormatProvider);
+  let template = _.template(noWhiteSpace(require('ui/stringify/types/_source.html')));
 
   _.class(Source).inherits(FieldFormat);
   function Source(params) {
@@ -20,15 +20,15 @@ export default function _SourceFormatProvider(Private, shortDotsFilter) {
     html: function sourceToHtml(source, field, hit) {
       if (!field) return this.getConverter('text')(source, field, hit);
 
-      var highlights = (hit && hit.highlight) || {};
-      var formatted = field.indexPattern.formatHit(hit);
-      var highlightPairs = [];
-      var sourcePairs = [];
+      let highlights = (hit && hit.highlight) || {};
+      let formatted = field.indexPattern.formatHit(hit);
+      let highlightPairs = [];
+      let sourcePairs = [];
 
       _.keys(formatted).forEach(function (key) {
-        var pairs = highlights[key] ? highlightPairs : sourcePairs;
-        var field = shortDotsFilter(key);
-        var val = formatted[key];
+        let pairs = highlights[key] ? highlightPairs : sourcePairs;
+        let field = shortDotsFilter(key);
+        let val = formatted[key];
         pairs.push([field, val]);
       }, []);
 
diff --git a/src/ui/public/stringify/types/string.js b/src/ui/public/stringify/types/string.js
index 7b0a4583cb2e..3db37865534e 100644
--- a/src/ui/public/stringify/types/string.js
+++ b/src/ui/public/stringify/types/string.js
@@ -2,7 +2,7 @@ import _ from 'lodash';
 import 'ui/field_format_editor/samples/samples';
 import IndexPatternsFieldFormatProvider from 'ui/index_patterns/_field_format/field_format';
 export default function StringFormatProvider(Private) {
-  var FieldFormat = Private(IndexPatternsFieldFormatProvider);
+  let FieldFormat = Private(IndexPatternsFieldFormatProvider);
 
 
   _.class(_String).inherits(FieldFormat);
diff --git a/src/ui/public/stringify/types/truncate.js b/src/ui/public/stringify/types/truncate.js
index 1ad69fc4fc92..666add881958 100644
--- a/src/ui/public/stringify/types/truncate.js
+++ b/src/ui/public/stringify/types/truncate.js
@@ -2,8 +2,8 @@ import _ from 'lodash';
 
 import IndexPatternsFieldFormatProvider from 'ui/index_patterns/_field_format/field_format';
 export default function TruncateFormatProvider(Private) {
-  var FieldFormat = Private(IndexPatternsFieldFormatProvider);
-  var omission = '...';
+  let FieldFormat = Private(IndexPatternsFieldFormatProvider);
+  let omission = '...';
 
   _.class(Truncate).inherits(FieldFormat);
 
@@ -16,7 +16,7 @@ export default function TruncateFormatProvider(Private) {
   Truncate.fieldType = ['string'];
 
   Truncate.prototype._convert = function (val) {
-    var length = this.param('fieldLength');
+    let length = this.param('fieldLength');
     if (length > 0) {
       return _.trunc(val, {
         'length': length + omission.length,
diff --git a/src/ui/public/stringify/types/url.js b/src/ui/public/stringify/types/url.js
index 510a0d3afa1c..eb1c46aeaaaf 100644
--- a/src/ui/public/stringify/types/url.js
+++ b/src/ui/public/stringify/types/url.js
@@ -5,7 +5,7 @@ import IndexPatternsFieldFormatProvider from 'ui/index_patterns/_field_format/fi
 import urlTemplate from 'ui/stringify/editors/url.html';
 export default function UrlFormatProvider(Private, highlightFilter) {
 
-  var FieldFormat = Private(IndexPatternsFieldFormatProvider);
+  let FieldFormat = Private(IndexPatternsFieldFormatProvider);
 
 
   _.class(Url).inherits(FieldFormat);
@@ -31,7 +31,7 @@ export default function UrlFormatProvider(Private, highlightFilter) {
     template: urlTemplate,
     controllerAs: 'url',
     controller: function ($scope) {
-      var iconPattern = '/bundles/src/ui/public/stringify/icons/{{value}}.png';
+      let iconPattern = '/bundles/src/ui/public/stringify/icons/{{value}}.png';
 
       this.samples = {
         a: [ 'john', '/some/pathname/asset.png', 1234 ],
@@ -39,7 +39,7 @@ export default function UrlFormatProvider(Private, highlightFilter) {
       };
 
       $scope.$watch('editor.formatParams.type', function (type, prev) {
-        var params = $scope.editor.formatParams;
+        let params = $scope.editor.formatParams;
         if (type === 'img' && type !== prev && !params.urlTemplate) {
           params.urlTemplate = iconPattern;
         }
@@ -60,7 +60,7 @@ export default function UrlFormatProvider(Private, highlightFilter) {
   ];
 
   Url.prototype._formatUrl = function (value) {
-    var template = this.param('urlTemplate');
+    let template = this.param('urlTemplate');
     if (!template) return value;
 
     return this._compileTemplate(template)({
@@ -70,7 +70,7 @@ export default function UrlFormatProvider(Private, highlightFilter) {
   };
 
   Url.prototype._formatLabel = function (value, url) {
-    var template = this.param('labelTemplate');
+    let template = this.param('labelTemplate');
     if (url == null) url = this._formatUrl(value);
     if (!template) return url;
 
@@ -86,8 +86,8 @@ export default function UrlFormatProvider(Private, highlightFilter) {
     },
 
     html: function (rawValue, field, hit) {
-      var url = _.escape(this._formatUrl(rawValue));
-      var label = _.escape(this._formatLabel(rawValue, url));
+      let url = _.escape(this._formatUrl(rawValue));
+      let label = _.escape(this._formatLabel(rawValue, url));
 
       switch (this.param('type')) {
         case 'img':
@@ -103,19 +103,19 @@ export default function UrlFormatProvider(Private, highlightFilter) {
   };
 
   Url.prototype._compileTemplate = function (template) {
-    var parts = template.split(Url.templateMatchRE).map(function (part, i) {
+    let parts = template.split(Url.templateMatchRE).map(function (part, i) {
       // trim all the odd bits, the variable names
       return (i % 2) ? part.trim() : part;
     });
 
     return function (locals) {
       // replace all the odd bits with their local var
-      var output = '';
-      var i = -1;
+      let output = '';
+      let i = -1;
       while (++i < parts.length) {
         if (i % 2) {
           if (locals.hasOwnProperty(parts[i])) {
-            var local = locals[parts[i]];
+            let local = locals[parts[i]];
             output += local == null ? '' : local;
           }
         } else {
diff --git a/src/ui/public/style_compile/style_compile.js b/src/ui/public/style_compile/style_compile.js
index cebd9a8ee7e1..4ec2bd7367c0 100644
--- a/src/ui/public/style_compile/style_compile.js
+++ b/src/ui/public/style_compile/style_compile.js
@@ -2,15 +2,15 @@ import _ from 'lodash';
 import $ from 'jquery';
 import 'ui/config';
 import uiModules from 'ui/modules';
-var $style = $('<style>').appendTo('head').attr('id', 'style-compile');
+let $style = $('<style>').appendTo('head').attr('id', 'style-compile');
 
 
 uiModules
 .get('kibana')
 .run(function ($rootScope, $compile, config) {
-  var truncateGradientHeight = 15;
-  var template = _.template(require('./style_compile.css.tmpl'));
-  var locals = {};
+  let truncateGradientHeight = 15;
+  let template = _.template(require('./style_compile.css.tmpl'));
+  let locals = {};
 
   // watch the value of the truncate:maxHeight config param
   $rootScope.$watch(function () {
diff --git a/src/ui/public/template_vis_type/template_renderbot.js b/src/ui/public/template_vis_type/template_renderbot.js
index 19040d61f3f1..c8dfac175b49 100644
--- a/src/ui/public/template_vis_type/template_renderbot.js
+++ b/src/ui/public/template_vis_type/template_renderbot.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 import VisRenderbotProvider from 'ui/vis/renderbot';
 export default function TemplateRenderbotFactory(Private, $compile, $rootScope) {
-  var Renderbot = Private(VisRenderbotProvider);
+  let Renderbot = Private(VisRenderbotProvider);
 
   _.class(TemplateRenderbot).inherits(Renderbot);
   function TemplateRenderbot(vis, $el, uiState) {
diff --git a/src/ui/public/template_vis_type/template_vis_type.js b/src/ui/public/template_vis_type/template_vis_type.js
index d9c7059e996f..3203b047ac58 100644
--- a/src/ui/public/template_vis_type/template_vis_type.js
+++ b/src/ui/public/template_vis_type/template_vis_type.js
@@ -2,8 +2,8 @@ import _ from 'lodash';
 import VisVisTypeProvider from 'ui/vis/vis_type';
 import TemplateVisTypeTemplateRenderbotProvider from 'ui/template_vis_type/template_renderbot';
 export default function TemplateVisTypeFactory(Private) {
-  var VisType = Private(VisVisTypeProvider);
-  var TemplateRenderbot = Private(TemplateVisTypeTemplateRenderbotProvider);
+  let VisType = Private(VisVisTypeProvider);
+  let TemplateRenderbot = Private(TemplateVisTypeTemplateRenderbotProvider);
 
   _.class(TemplateVisType).inherits(VisType);
   function TemplateVisType(opts) {
diff --git a/src/ui/public/test_harness/test_harness.js b/src/ui/public/test_harness/test_harness.js
index 4fb4a3e77964..9b68ffea17a1 100644
--- a/src/ui/public/test_harness/test_harness.js
+++ b/src/ui/public/test_harness/test_harness.js
@@ -18,8 +18,8 @@ $('body').attr('id', 'test-harness-body'); // so we can make high priority selec
 
 
 /*** Setup seeded random ***/
-var seedInput = parse(window.location.href, true).query.seed;
-var seed = _.add(seedInput, 0) || Date.now();
+let seedInput = parse(window.location.href, true).query.seed;
+let seed = _.add(seedInput, 0) || Date.now();
 Math.random = _.bindKey(new Nonsense(seed), 'frac');
 Math.random.nonsense = new Nonsense(seed);
 console.log('Random-ness seed: ' + seed);
@@ -38,7 +38,7 @@ before(function () {
   this.timeout(30000);
 
   let mapper;
-  var Runner = window.Mocha.Runner;
+  let Runner = window.Mocha.Runner;
 
   Runner.prototype.emit = _.wrap(Runner.prototype.emit, function (emit, event, test, err) {
     if (err && mapper) err = mapper.mapError(err);
diff --git a/src/ui/public/time_buckets/calc_auto_interval.js b/src/ui/public/time_buckets/calc_auto_interval.js
index 69e2ad3150c2..4c0889ffe16c 100644
--- a/src/ui/public/time_buckets/calc_auto_interval.js
+++ b/src/ui/public/time_buckets/calc_auto_interval.js
@@ -3,7 +3,7 @@ import moment from 'moment';
 export default function DateIntervalRoundingRulesProvider() {
   // these are the rounding rules used by roundInterval()
 
-  var roundingRules = [
+  let roundingRules = [
     [ d(500, 'ms'), d(100, 'ms') ],
     [ d(5, 'second'), d(1, 'second') ],
     [ d(7.5, 'second'), d(5, 'second') ],
@@ -22,16 +22,16 @@ export default function DateIntervalRoundingRulesProvider() {
     [ Infinity, d(1, 'year') ]
   ];
 
-  var revRoundingRules = roundingRules.slice(0).reverse();
+  let revRoundingRules = roundingRules.slice(0).reverse();
 
   function find(rules, check, last) {
     function pick(buckets, duration) {
-      var target = duration / buckets;
+      let target = duration / buckets;
       let lastResp;
 
-      for (var i = 0; i < rules.length; i++) {
-        var rule = rules[i];
-        var resp = check(rule[0], rule[1], target);
+      for (let i = 0; i < rules.length; i++) {
+        let rule = rules[i];
+        let resp = check(rule[0], rule[1], target);
 
         if (resp == null) {
           if (!last) continue;
@@ -44,12 +44,12 @@ export default function DateIntervalRoundingRulesProvider() {
       }
 
       // fallback to just a number of milliseconds, ensure ms is >= 1
-      var ms = Math.max(Math.floor(target), 1);
+      let ms = Math.max(Math.floor(target), 1);
       return moment.duration(ms, 'ms');
     }
 
     return function (buckets, duration) {
-      var interval = pick(buckets, duration);
+      let interval = pick(buckets, duration);
       if (interval) return moment.duration(interval._data);
     };
   }
diff --git a/src/ui/public/time_buckets/calc_es_interval.js b/src/ui/public/time_buckets/calc_es_interval.js
index a359926d84a5..cfb18cc94aa6 100644
--- a/src/ui/public/time_buckets/calc_es_interval.js
+++ b/src/ui/public/time_buckets/calc_es_interval.js
@@ -2,8 +2,8 @@ import moment from 'moment';
 import dateMath from 'ui/utils/date_math';
 export default function () {
 
-  var unitsDesc = dateMath.unitsDesc;
-  var largeMax = unitsDesc.indexOf('M');
+  let unitsDesc = dateMath.unitsDesc;
+  let largeMax = unitsDesc.indexOf('M');
 
   /**
    * Convert a moment.duration into an es
@@ -14,9 +14,9 @@ export default function () {
    * @return {object}
    */
   function esDuration(duration) {
-    for (var i = 0; i < unitsDesc.length; i++) {
-      var unit = unitsDesc[i];
-      var val = duration.as(unit);
+    for (let i = 0; i < unitsDesc.length; i++) {
+      let unit = unitsDesc[i];
+      let val = duration.as(unit);
       // find a unit that rounds neatly
       if (val >= 1 && Math.floor(val) === val) {
 
@@ -35,7 +35,7 @@ export default function () {
       }
     }
 
-    var ms = duration.as('ms');
+    let ms = duration.as('ms');
     return {
       value: ms,
       unit: 'ms',
diff --git a/src/ui/public/time_buckets/time_buckets.js b/src/ui/public/time_buckets/time_buckets.js
index 24c3bdd7a348..d1417fe8b784 100644
--- a/src/ui/public/time_buckets/time_buckets.js
+++ b/src/ui/public/time_buckets/time_buckets.js
@@ -6,9 +6,9 @@ import TimeBucketsCalcAutoIntervalProvider from 'ui/time_buckets/calc_auto_inter
 import TimeBucketsCalcEsIntervalProvider from 'ui/time_buckets/calc_es_interval';
 export default function IntervalHelperProvider(Private, timefilter, config) {
 
-  var calcAuto = Private(TimeBucketsCalcAutoIntervalProvider);
-  var calcEsInterval = Private(TimeBucketsCalcEsIntervalProvider);
-  var tzOffset = moment().format('Z');
+  let calcAuto = Private(TimeBucketsCalcAutoIntervalProvider);
+  let calcEsInterval = Private(TimeBucketsCalcEsIntervalProvider);
+  let tzOffset = moment().format('Z');
 
   function isValidMoment(m) {
     return m && ('isValid' in m) && m.isValid();
@@ -51,11 +51,11 @@ export default function IntervalHelperProvider(Private, timefilter, config) {
       bounds = _.isArray(input) ? input : [];
     }
 
-    var moments = _(bounds)
+    let moments = _(bounds)
     .map(_.ary(moment, 1))
     .sortBy(Number);
 
-    var valid = moments.size() === 2 && moments.every(isValidMoment);
+    let valid = moments.size() === 2 && moments.every(isValidMoment);
     if (!valid) {
       this.clearBounds();
       throw new Error('invalid bounds set: ' + input);
@@ -133,7 +133,7 @@ export default function IntervalHelperProvider(Private, timefilter, config) {
    * @param {object|string|moment.duration} input - see desc
    */
   TimeBuckets.prototype.setInterval = function (input) {
-    var interval = input;
+    let interval = input;
 
     // selection object -> val
     if (_.isObject(input)) {
@@ -197,13 +197,13 @@ export default function IntervalHelperProvider(Private, timefilter, config) {
    * @return {[type]} [description]
    */
   TimeBuckets.prototype.getInterval = function () {
-    var self = this;
-    var duration = self.getDuration();
+    let self = this;
+    let duration = self.getDuration();
     return decorateInterval(maybeScaleInterval(readInterval()));
 
     // either pull the interval from state or calculate the auto-interval
     function readInterval() {
-      var interval = self._i;
+      let interval = self._i;
       if (moment.isDuration(interval)) return interval;
       return calcAuto.near(config.get('histogram:barTarget'), duration);
     }
@@ -212,8 +212,8 @@ export default function IntervalHelperProvider(Private, timefilter, config) {
     function maybeScaleInterval(interval) {
       if (!self.hasBounds()) return interval;
 
-      var maxLength = config.get('histogram:maxBars');
-      var approxLen = duration / interval;
+      let maxLength = config.get('histogram:maxBars');
+      let approxLen = duration / interval;
       let scaled;
 
       if (approxLen > maxLength) {
@@ -234,13 +234,13 @@ export default function IntervalHelperProvider(Private, timefilter, config) {
 
     // append some TimeBuckets specific props to the interval
     function decorateInterval(interval) {
-      var esInterval = calcEsInterval(interval);
+      let esInterval = calcEsInterval(interval);
       interval.esValue = esInterval.value;
       interval.esUnit = esInterval.unit;
       interval.expression = esInterval.expression;
       interval.overflow = duration > interval ? moment.duration(interval - duration) : false;
 
-      var prettyUnits = moment.normalizeUnits(esInterval.unit);
+      let prettyUnits = moment.normalizeUnits(esInterval.unit);
       if (esInterval.value === 1) {
         interval.description = prettyUnits;
       } else {
@@ -263,11 +263,11 @@ export default function IntervalHelperProvider(Private, timefilter, config) {
    * @return {string}
    */
   TimeBuckets.prototype.getScaledDateFormat = function () {
-    var interval = this.getInterval();
-    var rules = config.get('dateFormat:scaled');
+    let interval = this.getInterval();
+    let rules = config.get('dateFormat:scaled');
 
-    for (var i = rules.length - 1; i >= 0; i--) {
-      var rule = rules[i];
+    for (let i = rules.length - 1; i >= 0; i--) {
+      let rule = rules[i];
       if (!rule[0] || interval >= moment.duration(rule[0])) {
         return rule[1];
       }
@@ -278,23 +278,23 @@ export default function IntervalHelperProvider(Private, timefilter, config) {
 
 
   TimeBuckets.__cached__ = function (self) {
-    var cache = {};
-    var sameMoment = same(moment.isMoment);
-    var sameDuration = same(moment.isDuration);
+    let cache = {};
+    let sameMoment = same(moment.isMoment);
+    let sameDuration = same(moment.isDuration);
 
-    var desc = {
+    let desc = {
       __cached__: {
         value: self
       },
     };
 
-    var breakers = {
+    let breakers = {
       setBounds: 'bounds',
       clearBounds: 'bounds',
       setInterval: 'interval'
     };
 
-    var resources = {
+    let resources = {
       bounds: {
         setup: function () {
           return [self._lb, self._ub];
@@ -326,16 +326,16 @@ export default function IntervalHelperProvider(Private, timefilter, config) {
     }
 
     function cacheBreaker(prop) {
-      var resource = resources[breakers[prop]];
-      var setup = resource.setup;
-      var changes = resource.changes;
-      var deps = resource.deps;
-      var fn = self[prop];
+      let resource = resources[breakers[prop]];
+      let setup = resource.setup;
+      let changes = resource.changes;
+      let deps = resource.deps;
+      let fn = self[prop];
 
       return {
         value: function cacheBreaker(input) {
-          var prev = setup.call(self);
-          var ret = fn.apply(self, arguments);
+          let prev = setup.call(self);
+          let ret = fn.apply(self, arguments);
 
           if (changes.call(self, prev)) {
             cache = {};
diff --git a/src/ui/public/timefilter/lib/diff_interval.js b/src/ui/public/timefilter/lib/diff_interval.js
index 7d2d38a554c6..9137e8d9dc65 100644
--- a/src/ui/public/timefilter/lib/diff_interval.js
+++ b/src/ui/public/timefilter/lib/diff_interval.js
@@ -1,10 +1,10 @@
 import _ from 'lodash';
 import UtilsDiffTimePickerValsProvider from 'ui/utils/diff_time_picker_vals';
 export default function diffTimeProvider(Private) {
-  var diff = Private(UtilsDiffTimePickerValsProvider);
+  let diff = Private(UtilsDiffTimePickerValsProvider);
 
   return function (self) {
-    var oldRefreshInterval = _.clone(self.refreshInterval);
+    let oldRefreshInterval = _.clone(self.refreshInterval);
 
     return function () {
       if (diff(self.refreshInterval, oldRefreshInterval)) {
diff --git a/src/ui/public/timefilter/lib/diff_time.js b/src/ui/public/timefilter/lib/diff_time.js
index 4728670a7fa0..39c1204cb46f 100644
--- a/src/ui/public/timefilter/lib/diff_time.js
+++ b/src/ui/public/timefilter/lib/diff_time.js
@@ -1,10 +1,10 @@
 import _ from 'lodash';
 import UtilsDiffTimePickerValsProvider from 'ui/utils/diff_time_picker_vals';
 export default function diffTimeProvider(Private) {
-  var diff = Private(UtilsDiffTimePickerValsProvider);
+  let diff = Private(UtilsDiffTimePickerValsProvider);
 
   return function (self) {
-    var oldTime = _.clone(self.time);
+    let oldTime = _.clone(self.time);
     return function () {
       if (diff(self.time, oldTime)) {
         self.emit('update');
diff --git a/src/ui/public/timefilter/timefilter.js b/src/ui/public/timefilter/timefilter.js
index 55da9e55a992..fdb8c608862f 100644
--- a/src/ui/public/timefilter/timefilter.js
+++ b/src/ui/public/timefilter/timefilter.js
@@ -20,12 +20,12 @@ uiModules
 .get('kibana')
 .service('timefilter', function (Private, globalState, $rootScope, config) {
 
-  var Events = Private(EventsProvider);
-  var diff = Private(UtilsDiffTimePickerValsProvider);
+  let Events = Private(EventsProvider);
+  let diff = Private(UtilsDiffTimePickerValsProvider);
 
 
   function convertISO8601(stringTime) {
-    var obj = moment(stringTime, 'YYYY-MM-DDTHH:mm:ss.SSSZ', true);
+    let obj = moment(stringTime, 'YYYY-MM-DDTHH:mm:ss.SSSZ', true);
     return obj.isValid() ? obj : stringTime;
   }
 
@@ -33,9 +33,9 @@ uiModules
   function Timefilter() {
     Timefilter.Super.call(this);
 
-    var self = this;
-    var diffTime = Private(TimefilterLibDiffTimeProvider)(self);
-    var diffInterval = Private(TimefilterLibDiffIntervalProvider)(self);
+    let self = this;
+    let diffTime = Private(TimefilterLibDiffTimeProvider)(self);
+    let diffInterval = Private(TimefilterLibDiffIntervalProvider)(self);
 
     self.enabled = false;
 
@@ -45,8 +45,8 @@ uiModules
     });
 
     self.consumeDefaults = _.once(function () {
-      var timeDefaults = config.get('timepicker:timeDefaults');
-      var refreshIntervalDefaults = config.get('timepicker:refreshIntervalDefaults');
+      let timeDefaults = config.get('timepicker:timeDefaults');
+      let refreshIntervalDefaults = config.get('timepicker:refreshIntervalDefaults');
 
       // These can be date math strings or moments.
       self.time = _.defaults(globalState.time || {}, timeDefaults);
@@ -54,8 +54,8 @@ uiModules
 
       globalState.on('fetch_with_changes', function () {
         // clone and default to {} in one
-        var newTime = _.defaults({}, globalState.time, timeDefaults);
-        var newRefreshInterval = _.defaults({}, globalState.refreshInterval, refreshIntervalDefaults);
+        let newTime = _.defaults({}, globalState.time, timeDefaults);
+        let newRefreshInterval = _.defaults({}, globalState.refreshInterval, refreshIntervalDefaults);
 
         if (newTime) {
           if (newTime.to) newTime.to = convertISO8601(newTime.to);
@@ -85,10 +85,10 @@ uiModules
 
   Timefilter.prototype.get = function (indexPattern) {
     let filter;
-    var timefield = indexPattern.timeFieldName && _.find(indexPattern.fields, {name: indexPattern.timeFieldName});
+    let timefield = indexPattern.timeFieldName && _.find(indexPattern.fields, {name: indexPattern.timeFieldName});
 
     if (timefield) {
-      var bounds = this.getBounds();
+      let bounds = this.getBounds();
       filter = {range : {}};
       filter.range[timefield.name] = {
         gte: bounds.min.valueOf(),
diff --git a/src/ui/public/timepicker/quick_ranges.js b/src/ui/public/timepicker/quick_ranges.js
index 618ca023d9a4..78b7c33b3fcc 100644
--- a/src/ui/public/timepicker/quick_ranges.js
+++ b/src/ui/public/timepicker/quick_ranges.js
@@ -1,5 +1,5 @@
 import uiModules from 'ui/modules';
-var module = uiModules.get('kibana');
+let module = uiModules.get('kibana');
 
 module.constant('quickRanges', [
   { from: 'now/d',    to: 'now/d',    display: 'Today',                 section: 0 },
diff --git a/src/ui/public/timepicker/refresh_intervals.js b/src/ui/public/timepicker/refresh_intervals.js
index 9736e99547dc..3845f2110e68 100644
--- a/src/ui/public/timepicker/refresh_intervals.js
+++ b/src/ui/public/timepicker/refresh_intervals.js
@@ -1,5 +1,5 @@
 import uiModules from 'ui/modules';
-var module = uiModules.get('kibana');
+let module = uiModules.get('kibana');
 
 module.constant('refreshIntervals', [
   { value : 0, display: 'Off', section: 0},
diff --git a/src/ui/public/timepicker/time_units.js b/src/ui/public/timepicker/time_units.js
index a3177dc8126f..da8960a2df64 100644
--- a/src/ui/public/timepicker/time_units.js
+++ b/src/ui/public/timepicker/time_units.js
@@ -1,5 +1,5 @@
 import uiModules from 'ui/modules';
-var module = uiModules.get('kibana');
+let module = uiModules.get('kibana');
 
 module.constant('timeUnits', {
   s: 'second',
diff --git a/src/ui/public/timepicker/timepicker.js b/src/ui/public/timepicker/timepicker.js
index ea5e9c174ffd..2104bb41bec4 100644
--- a/src/ui/public/timepicker/timepicker.js
+++ b/src/ui/public/timepicker/timepicker.js
@@ -10,8 +10,8 @@ import 'ui/timepicker/refresh_intervals';
 import 'ui/timepicker/time_units';
 import 'ui/timepicker/kbn_global_timepicker';
 import uiModules from 'ui/modules';
-var module = uiModules.get('ui/timepicker');
-var notify = new Notifier({
+let module = uiModules.get('ui/timepicker');
+let notify = new Notifier({
   location: 'timepicker',
 });
 
@@ -28,7 +28,7 @@ module.directive('kbnTimepicker', function (quickRanges, timeUnits, refreshInter
     },
     template: html,
     controller: function ($scope) {
-      var init = function () {
+      let init = function () {
         $scope.setMode($scope.mode);
       };
 
@@ -78,8 +78,8 @@ module.directive('kbnTimepicker', function (quickRanges, timeUnits, refreshInter
           case 'quick':
             break;
           case 'relative':
-            var fromParts = $scope.from.toString().split('-');
-            var relativeParts = [];
+            let fromParts = $scope.from.toString().split('-');
+            let relativeParts = [];
 
             // Try to parse the relative time, if we can't use moment duration to guestimate
             if ($scope.to.toString() === 'now' && fromParts[0] === 'now' && fromParts[1]) {
@@ -89,11 +89,11 @@ module.directive('kbnTimepicker', function (quickRanges, timeUnits, refreshInter
               $scope.relative.count = parseInt(relativeParts[1], 10);
               $scope.relative.unit = relativeParts[2];
             } else {
-              var duration = moment.duration(moment().diff(dateMath.parse($scope.from)));
-              var units = _.pluck(_.clone($scope.relativeOptions).reverse(), 'value');
+              let duration = moment.duration(moment().diff(dateMath.parse($scope.from)));
+              let units = _.pluck(_.clone($scope.relativeOptions).reverse(), 'value');
               if ($scope.from.toString().split('/')[1]) $scope.relative.round = true;
-              for (var i = 0; i < units.length; i++) {
-                var as = duration.as(units[i]);
+              for (let i = 0; i < units.length; i++) {
+                let as = duration.as(units[i]);
                 if (as > 1) {
                   $scope.relative.count = Math.round(as);
                   $scope.relative.unit = units[i];
@@ -125,7 +125,7 @@ module.directive('kbnTimepicker', function (quickRanges, timeUnits, refreshInter
       };
 
       $scope.formatRelative = function () {
-        var parsed = dateMath.parse(getRelativeString());
+        let parsed = dateMath.parse(getRelativeString());
         $scope.relative.preview =  parsed ? parsed.format($scope.format) : undefined;
         return parsed;
       };
diff --git a/src/ui/public/typeahead/_input.js b/src/ui/public/typeahead/_input.js
index 89ae28a5f525..88d8130102b4 100644
--- a/src/ui/public/typeahead/_input.js
+++ b/src/ui/public/typeahead/_input.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 import 'ui/notify/directives';
 import uiModules from 'ui/modules';
-var typeahead = uiModules.get('kibana/typeahead');
+let typeahead = uiModules.get('kibana/typeahead');
 
 
 typeahead.directive('kbnTypeaheadInput', function ($rootScope) {
@@ -11,8 +11,8 @@ typeahead.directive('kbnTypeaheadInput', function ($rootScope) {
     require: ['^ngModel', '^kbnTypeahead'],
 
     link: function ($scope, $el, $attr, deps) {
-      var model = deps[0];
-      var typeaheadCtrl = deps[1];
+      let model = deps[0];
+      let typeaheadCtrl = deps[1];
 
       typeaheadCtrl.setInputModel(model);
 
diff --git a/src/ui/public/typeahead/_items.js b/src/ui/public/typeahead/_items.js
index 2fefbea59f3a..9f2bf9941c0e 100644
--- a/src/ui/public/typeahead/_items.js
+++ b/src/ui/public/typeahead/_items.js
@@ -2,7 +2,7 @@ import _ from 'lodash';
 import listTemplate from 'ui/typeahead/partials/typeahead-items.html';
 import 'ui/notify/directives';
 import uiModules from 'ui/modules';
-var typeahead = uiModules.get('kibana/typeahead');
+let typeahead = uiModules.get('kibana/typeahead');
 
 
 typeahead.directive('kbnTypeaheadItems', function () {
diff --git a/src/ui/public/typeahead/typeahead.js b/src/ui/public/typeahead/typeahead.js
index 336e2ed1f287..a97ffd4f6f63 100644
--- a/src/ui/public/typeahead/typeahead.js
+++ b/src/ui/public/typeahead/typeahead.js
@@ -3,11 +3,11 @@ import 'ui/typeahead/typeahead.less';
 import 'ui/typeahead/_input';
 import 'ui/typeahead/_items';
 import uiModules from 'ui/modules';
-var typeahead = uiModules.get('kibana/typeahead');
+let typeahead = uiModules.get('kibana/typeahead');
 
 
 typeahead.directive('kbnTypeahead', function () {
-  var keyMap = {
+  let keyMap = {
     ESC: 27,
     UP: 38,
     DOWN: 40,
@@ -23,7 +23,7 @@ typeahead.directive('kbnTypeahead', function () {
     controllerAs: 'typeahead',
 
     controller: function ($scope, $element, $timeout, PersistedLog, config) {
-      var self = this;
+      let self = this;
       self.form = $element.closest('form');
       self.query = '';
       self.hidden = true;
@@ -76,7 +76,7 @@ typeahead.directive('kbnTypeahead', function () {
       };
 
       self.activateNext = function () {
-        var index = self.getActiveIndex();
+        let index = self.getActiveIndex();
         if (index == null) {
           index = 0;
         } else if (index < $scope.filteredItems.length - 1) {
@@ -87,7 +87,7 @@ typeahead.directive('kbnTypeahead', function () {
       };
 
       self.activatePrev = function () {
-        var index = self.getActiveIndex();
+        let index = self.getActiveIndex();
 
         if (index > 0 && index != null) {
           --index;
@@ -138,7 +138,7 @@ typeahead.directive('kbnTypeahead', function () {
       };
 
       self.keypressHandler = function (ev) {
-        var keyCode = ev.which || ev.keyCode;
+        let keyCode = ev.which || ev.keyCode;
 
         if (self.focused) {
           self.hidden = false;
@@ -194,11 +194,11 @@ typeahead.directive('kbnTypeahead', function () {
         }
 
         // update the filteredItems using the query
-        var beginningMatches = $scope.items.filter(function (item) {
+        let beginningMatches = $scope.items.filter(function (item) {
           return item.indexOf(query) === 0;
         });
 
-        var otherMatches = $scope.items.filter(function (item) {
+        let otherMatches = $scope.items.filter(function (item) {
           return item.indexOf(query) > 0;
         });