diff --git a/.eslintignore b/.eslintignore
index a7282e5a8..2c66a52c4 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -1,2 +1,5 @@
 index_bundle.js
 config.js
+diff.js
+diverged.js
+divergedWorker.js
diff --git a/compare/output/diverged.js b/compare/output/diverged.js
index 6f9ff2746..7e23d77be 100644
--- a/compare/output/diverged.js
+++ b/compare/output/diverged.js
@@ -12,12 +12,14 @@ if (typeof require !== 'undefined') {
     }
 }
 
+const rowSpread = 1;
+
 const spread = 50; // range of adjacent pixels to aggregate when calculating diff
 const IS_ADDED_WORD = '0_255_0_255';
 const IS_REMOVED_WORD = '255_0_0_255';
 const IS_ADDED_AND_REMOVED_WORD = '0_255_255_255';
 const IS_SAME_WORD = '';
-const OPACITY = '30'; // 0-255 range
+const OPACITY = '40'; // 0-255 range
 
 /**
  * Applies meyers-diff algorithm to imageData formatted arrays
@@ -122,6 +124,7 @@ function reduceColumnDiffRaw(columnDiffs, h, w) {
         for (let depthIndex = 0; depthIndex < columnDiff.length; depthIndex++) {
             let segmentLength = 0;
 
+            // Categorize the current segment
             if (columnDiff[depthIndex].removed) {
                 segmentLength = columnDiff[depthIndex].count;
                 removedCounter += segmentLength;
@@ -137,7 +140,6 @@ function reduceColumnDiffRaw(columnDiffs, h, w) {
                     resultClass = IS_SAME_WORD;
                 }
 
-
                 segmentLength = columnDiff[depthIndex].count;
 
                 if (removedCounter > 0) {
@@ -151,6 +153,7 @@ function reduceColumnDiffRaw(columnDiffs, h, w) {
                 }
             }
 
+            // Limit segmentLength to total length of column
             if (!segmentLength) {
                 continue;
             } else {
@@ -220,26 +223,47 @@ function groupAdjacent(columns, spread, h, w) {
         return interpolated;
     }
 
-    function getCompositeColumnDepthValues(columns, range, depth) {
-        return range.reduce((acc, column) => {
+    function getCompositeColumnDepthValues(columns, sequence, depth) {
+        return sequence.reduce((acc, column) => {
             return acc.concat(columns[column][depth]);
         }, [])
     }
 
-    const interpolatedColumnsValues = new Array();
-    let i = 0;
-    while (i < w) {
-        const adjacentBounds = getAdjacentArrayBounds(i, spread, w);
-        const interpolatedColumns = getInterpolatedSequence(...adjacentBounds);
+    function getCompositeRowIndexValues(groupedColumns, sequence, column) {
+        return sequence.reduce((acc, depth) => {
+            return acc.concat(groupedColumns[column][depth]);
+        }, [])
+    }
+
+    const groupedColumns = new Array();
+    let columnPointer = 0;
+    while (columnPointer < w) {
+        const adjacentColumnBounds = getAdjacentArrayBounds(columnPointer, spread, w);
+        const interpolatedColumns = getInterpolatedSequence(...adjacentColumnBounds);
         
-        const columnComposite = new Array(h);
+        const columnComposite = new Array();
         for (var depth = 0; depth < h; depth++) {        
             columnComposite[depth] = getCompositeColumnDepthValues(columns, interpolatedColumns, depth).join('|');
         }
-        interpolatedColumnsValues.push(columnComposite);
-        i += spread;
+        groupedColumns.push(columnComposite);
+        columnPointer += spread;
+    }
+
+    const groupedRows = new Array();
+    if (rowSpread > 1) {
+        for (var index = 0; index < groupedColumns.length; index++) {
+            const rowComposite = new Array();
+            let depthPointer = 0;
+            while (depthPointer < h) {
+                const adjacentRowBounds = getAdjacentArrayBounds(depthPointer, rowSpread, h);
+                const interpolatedRows = getInterpolatedSequence(...adjacentRowBounds);
+                rowComposite.push(getCompositeRowIndexValues(groupedColumns, interpolatedRows, index).join(','));
+                depthPointer += rowSpread;
+            }
+            groupedRows[index] = rowComposite;
+        }
     }
-    return interpolatedColumnsValues;
+    return groupedRows.length ? groupedRows : groupedColumns ;
 }
 
 function ungroupAdjacent(grouped, spread, columnUnderlay, h, w) {
@@ -251,16 +275,18 @@ function ungroupAdjacent(grouped, spread, columnUnderlay, h, w) {
         return Math.floor(index / spread);
     }
 
+    // expand columns
     const ungrouped = new Array(w);
-    for (let i = 0; i < w; i++) {
-         if (!ungrouped[i]) {
-            ungrouped[i] = new Array(h);
+    for (let index = 0; index < w; index++) {
+         if (!ungrouped[index]) {
+            ungrouped[index] = new Array(h);
          }
 
-         const groupedIndex = mapUngroupedColumnIndexToGroupedIndex(i, spread);
-         for (let j = 0; j < h; j++) {
-            const value = grouped[groupedIndex][j].split('|')[0];
-            ungrouped[i][j] = value ? value : columnUnderlay[i][j].replace(/\d+$/, OPACITY);
+         const groupedIndexMap = mapUngroupedColumnIndexToGroupedIndex(index, spread);
+         for (let depth = 0; depth < h; depth++) {
+            const groupedDepthMap = rowSpread > 1 ? mapUngroupedColumnIndexToGroupedIndex(depth, rowSpread) : depth;
+            const value = grouped[groupedIndexMap][groupedDepthMap].split('|')[0];
+            ungrouped[index][depth] = value ? value : columnUnderlay[index][depth].replace(/\d+$/, OPACITY);
          }
     }
 
diff --git a/compare/output/divergedWorker.js b/compare/output/divergedWorker.js
index b2fbe58ef..c41d85e54 100644
--- a/compare/output/divergedWorker.js
+++ b/compare/output/divergedWorker.js
@@ -3,4 +3,4 @@ importScripts('diverged.js');
 self.addEventListener('message', function(e) {
   self.postMessage(diverged(...e.data.divergedInput));
   self.close();
-}, false);
\ No newline at end of file
+}, false);
diff --git a/compare/output/index_bundle.js b/compare/output/index_bundle.js
index a40dc73bd..3b48b730c 100644
--- a/compare/output/index_bundle.js
+++ b/compare/output/index_bundle.js
@@ -33625,16 +33625,18 @@ var ImageScrubber = function (_React$Component) {
 
       // TODO: halp. i don't haz context.
       var that = this;
-      // TODO: concurrency?
+
       function divergedWorker() {
         if (that.state.isLoading) {
           console.error('Diverged process is already running. Please hang on.');
           return;
         }
+
         if (divergedImage) {
           showScrubberDivergedImage(divergedImage);
           return;
         }
+
         showScrubberDivergedImage('');
         that.loadingDiverge(true);
 
diff --git a/test/configs/responsiveDemo.json b/test/configs/responsiveDemo.json
new file mode 100644
index 000000000..1e0cc6182
--- /dev/null
+++ b/test/configs/responsiveDemo.json
@@ -0,0 +1,54 @@
+{
+  "id": "responsiveDemoPage",
+  "viewports": [
+    {
+      "label": "phone",
+      "width": 320,
+      "height": 480
+    },
+    {
+      "label": "tablet",
+      "width": 1024,
+      "height": 768
+    }
+  ],
+  "onBeforeScript": "puppet/onBefore.js",
+  "onReadyScript": "puppet/onReady.js",
+  "scenarios": [
+    {
+      "label": "comparePage",
+      "cookiePath": "backstop_data/engine_scripts/cookies.json",
+      "url": "http://127.0.0.1:3000/responsiveDemoAlias/index.html",
+      "referenceUrl": "",
+      "readyEvent": "",
+      "readySelector": "",
+      "delay": 100,
+      "hideSelectors": [],
+      "removeSelectors": [],
+      "hoverSelector": "",
+      "clickSelector": "",
+      "postInteractionWait": 0,
+      "selectors": [],
+      "selectorExpansion": true,
+      "expect": 0,
+      "misMatchThreshold" : 0.1,
+      "requireSameDimensions": true
+    }
+  ],
+  "paths": {
+    "bitmaps_reference": "backstop_data/bitmaps_reference",
+    "bitmaps_test": "backstop_data/bitmaps_test",
+    "engine_scripts": "backstop_data/engine_scripts",
+    "html_report": "backstop_data/html_report",
+    "ci_report": "backstop_data/ci_report"
+  },
+  "report": ["browser"],
+  "engine": "puppeteer",
+  "engineOptions": {
+    "args": ["--no-sandbox"]
+  },
+  "asyncCaptureLimit": 5,
+  "asyncCompareLimit": 50,
+  "debug": false,
+  "debugWindow": false
+}
diff --git a/test/configs/responsiveDemoAlias b/test/configs/responsiveDemoAlias
new file mode 120000
index 000000000..ff62b3000
--- /dev/null
+++ b/test/configs/responsiveDemoAlias
@@ -0,0 +1 @@
+../../examples/responsiveDemo
\ No newline at end of file