diff --git a/internal/magic/text.go b/internal/magic/text.go
index d23bd9d5..a8778d86 100644
--- a/internal/magic/text.go
+++ b/internal/magic/text.go
@@ -251,6 +251,47 @@ func NdJson(raw []byte, limit uint32) bool {
 	return parsed > 2 && parsed == len(raw)
 }
 
+// Har matches a HAR Spec file.
+// Spec: http://www.softwareishard.com/blog/har-12-spec/
+func HAR(raw []byte, limit uint32) bool {
+	s := []byte(`"log"`)
+	si, sl := bytes.Index(raw, s), len(s)
+
+	if si == -1 {
+		return false
+	}
+
+	// If the "log" string is the suffix of the input,
+	// there is no need to search for the value of the key.
+	if si+sl == len(raw) {
+		return false
+	}
+	// Skip the "log" part.
+	raw = raw[si+sl:]
+	// Skip any whitespace before the colon.
+	raw = trimLWS(raw)
+	// Check for colon.
+	if len(raw) == 0 || raw[0] != ':' {
+		return false
+	}
+	// Skip any whitespace after the colon.
+	raw = trimLWS(raw[1:])
+
+	harJsonTypes := [][]byte{
+		[]byte(`"version"`),
+		[]byte(`"creator"`),
+		[]byte(`"entries"`),
+	}
+	for _, t := range harJsonTypes {
+		si := bytes.Index(raw, t)
+		if si > -1 {
+			return true
+		}
+	}
+
+	return false
+}
+
 // Svg matches a SVG file.
 func Svg(raw []byte, limit uint32) bool {
 	return bytes.Contains(raw, []byte("<svg"))
diff --git a/mimetype_test.go b/mimetype_test.go
index b357e016..72dbedda 100644
--- a/mimetype_test.go
+++ b/mimetype_test.go
@@ -69,6 +69,7 @@ var files = map[string]string{
 	"gml.gml":            "application/gml+xml",
 	"gpx.gpx":            "application/gpx+xml",
 	"gz.gz":              "application/gzip",
+	"har.har":            "application/json",
 	"hdr.hdr":            "image/vnd.radiance",
 	"heic.single.heic":   "image/heic",
 	"heif.heif":          "image/heif",
diff --git a/supported_mimes.md b/supported_mimes.md
index b7cbec47..ef989990 100644
--- a/supported_mimes.md
+++ b/supported_mimes.md
@@ -1,4 +1,4 @@
-## 163 Supported MIME types
+## 164 Supported MIME types
 This file is automatically generated when running tests. Do not edit manually.
 
 Extension | MIME type | Aliases
@@ -158,6 +158,7 @@ Extension | MIME type | Aliases
 **.py** | application/x-python | -
 **.json** | application/json | -
 **.geojson** | application/geo+json | -
+**.har** | application/json | -
 **.ndjson** | application/x-ndjson | -
 **.rtf** | text/rtf | -
 **.tcl** | text/x-tcl | application/x-tcl
diff --git a/testdata/har.har b/testdata/har.har
new file mode 100644
index 00000000..8d12372e
--- /dev/null
+++ b/testdata/har.har
@@ -0,0 +1,163 @@
+{
+  "log": {
+    "version": "1.2",
+    "creator": {
+      "name": "WebInspector",
+      "version": "537.36"
+    },
+    "pages": [
+      {
+        "startedDateTime": "2021-08-14T04:22:59.975Z",
+        "id": "page_2",
+        "title": "http://example.com/",
+        "pageTimings": {
+          "onContentLoad": 992.4480000008771,
+          "onLoad": 1054.7850000002654
+        }
+      }
+    ],
+    "entries": [
+      {
+        "_initiator": {
+          "type": "other"
+        },
+        "_priority": "VeryHigh",
+        "_resourceType": "document",
+        "cache": {},
+        "connection": "215113",
+        "pageref": "page_2",
+        "request": {
+          "method": "GET",
+          "url": "http://example.com/",
+          "httpVersion": "HTTP/1.1",
+          "headers": [
+            {
+              "name": "Host",
+              "value": "example.com"
+            },
+            {
+              "name": "Proxy-Connection",
+              "value": "keep-alive"
+            },
+            {
+              "name": "Pragma",
+              "value": "no-cache"
+            },
+            {
+              "name": "Cache-Control",
+              "value": "no-cache"
+            },
+            {
+              "name": "Upgrade-Insecure-Requests",
+              "value": "1"
+            },
+            {
+              "name": "User-Agent",
+              "value": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.164 Safari/537.36"
+            },
+            {
+              "name": "Accept",
+              "value": "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9"
+            },
+            {
+              "name": "Accept-Encoding",
+              "value": "gzip, deflate"
+            },
+            {
+              "name": "Accept-Language",
+              "value": "en-US,en;q=0.9"
+            }
+          ],
+          "queryString": [],
+          "cookies": [],
+          "headersSize": 467,
+          "bodySize": 0
+        },
+        "response": {
+          "status": 200,
+          "statusText": "OK",
+          "httpVersion": "HTTP/1.1",
+          "headers": [
+            {
+              "name": "Accept-Ranges",
+              "value": "bytes"
+            },
+            {
+              "name": "Age",
+              "value": "390086"
+            },
+            {
+              "name": "Cache-Control",
+              "value": "max-age=604800"
+            },
+            {
+              "name": "Content-Type",
+              "value": "text/html; charset=UTF-8"
+            },
+            {
+              "name": "Date",
+              "value": "Sat, 14 Aug 2021 04:23:00 GMT"
+            },
+            {
+              "name": "Etag",
+              "value": "\"3147526947\""
+            },
+            {
+              "name": "Expires",
+              "value": "Sat, 21 Aug 2021 04:23:00 GMT"
+            },
+            {
+              "name": "Last-Modified",
+              "value": "Thu, 17 Oct 2019 07:18:26 GMT"
+            },
+            {
+              "name": "Server",
+              "value": "ECS (dcb/7EC6)"
+            },
+            {
+              "name": "Vary",
+              "value": "Accept-Encoding"
+            },
+            {
+              "name": "X-Cache",
+              "value": "HIT"
+            },
+            {
+              "name": "Content-Length",
+              "value": "1256"
+            },
+            {
+              "name": "Proxy-Connection",
+              "value": "keep-alive"
+            }
+          ],
+          "cookies": [],
+          "content": {
+            "size": 1256,
+            "mimeType": "text/html",
+            "compression": 0,
+            "text": "<!doctype html>\n<html>\n<head>\n    <title>Example Domain</title>\n\n    <meta charset=\"utf-8\" />\n    <meta http-equiv=\"Content-type\" content=\"text/html; charset=utf-8\" />\n    <meta name=\"viewport\" content=\"width=device-width, initial-scale=1\" />\n    <style type=\"text/css\">\n    body {\n        background-color: #f0f0f2;\n        margin: 0;\n        padding: 0;\n        font-family: -apple-system, system-ui, BlinkMacSystemFont, \"Segoe UI\", \"Open Sans\", \"Helvetica Neue\", Helvetica, Arial, sans-serif;\n        \n    }\n    div {\n        width: 600px;\n        margin: 5em auto;\n        padding: 2em;\n        background-color: #fdfdff;\n        border-radius: 0.5em;\n        box-shadow: 2px 3px 7px 2px rgba(0,0,0,0.02);\n    }\n    a:link, a:visited {\n        color: #38488f;\n        text-decoration: none;\n    }\n    @media (max-width: 700px) {\n        div {\n            margin: 0 auto;\n            width: auto;\n        }\n    }\n    </style>    \n</head>\n\n<body>\n<div>\n    <h1>Example Domain</h1>\n    <p>This domain is for use in illustrative examples in documents. You may use this\n    domain in literature without prior coordination or asking for permission.</p>\n    <p><a href=\"https://www.iana.org/domains/example\">More information...</a></p>\n</div>\n</body>\n</html>\n"
+          },
+          "redirectURL": "",
+          "headersSize": 381,
+          "bodySize": 1256,
+          "_transferSize": 1637,
+          "_error": null
+        },
+        "serverIPAddress": "127.0.0.1",
+        "startedDateTime": "2021-08-14T04:22:59.968Z",
+        "time": 948.011000000406,
+        "timings": {
+          "blocked": 10.241999999793713,
+          "dns": -1,
+          "ssl": -1,
+          "connect": -1,
+          "send": 0.19499999999999984,
+          "wait": 936.1970000001099,
+          "receive": 1.3770000005024485,
+          "_blocked_queueing": 6.790999999793712
+        }
+      }
+    ]
+  }
+}
\ No newline at end of file
diff --git a/tree.go b/tree.go
index c9a1985c..e6e0296c 100644
--- a/tree.go
+++ b/tree.go
@@ -76,7 +76,8 @@ var (
 	oggVideo = newMIME("video/ogg", ".ogv", magic.OggVideo)
 	text     = newMIME("text/plain", ".txt", magic.Text, html, svg, xml, php, js, lua, perl, python, json, ndJson, rtf, tcl, csv, tsv, vCard, iCalendar, warc)
 	xml      = newMIME("text/xml", ".xml", magic.Xml, rss, atom, x3d, kml, xliff, collada, gml, gpx, tcx, amf, threemf, xfdf, owl2)
-	json     = newMIME("application/json", ".json", magic.Json, geoJson)
+	json     = newMIME("application/json", ".json", magic.Json, geoJson, har)
+	har      = newMIME("application/json", ".har", magic.HAR)
 	csv      = newMIME("text/csv", ".csv", magic.Csv)
 	tsv      = newMIME("text/tab-separated-values", ".tsv", magic.Tsv)
 	geoJson  = newMIME("application/geo+json", ".geojson", magic.GeoJson)