diff --git a/package.json b/package.json
index 4f227e312b..6f3ec2dafb 100644
--- a/package.json
+++ b/package.json
@@ -26,6 +26,7 @@
     "camp": "~16.2.3",
     "chrome-web-store-item-property": "~1.1.2",
     "dot": "~1.0.3",
+    "pretty-bytes": "^3.0.1",
     "gm": "^1.23.0",
     "json-autosave": "~1.1.2",
     "pdfkit": "~0.8.0",
diff --git a/server.js b/server.js
index dae571b0d2..5fe07b7a8d 100644
--- a/server.js
+++ b/server.js
@@ -31,6 +31,7 @@ var svg2img = require('./lib/svg-to-img.js');
 var loadLogos = require('./lib/load-logos.js');
 var githubAuth = require('./lib/github-auth.js');
 var querystring = require('querystring');
+var prettyBytes = require('pretty-bytes');
 var xml2js = require('xml2js');
 var serverSecrets = require('./lib/server-secrets');
 if (serverSecrets && serverSecrets.gh_client_id) {
@@ -3436,6 +3437,48 @@ cache(function(data, match, sendBadge, request) {
   });
 }));
 
+// GitHub file size.
+camp.route(/^\/github\/size\/([^\/]+)\/([^\/]+)\/(.*)\.(svg|png|gif|jpg|json)$/,
+cache(function(data, match, sendBadge, request) {
+  var user = match[1];  // eg, mashape
+  var repo = match[2];  // eg, apistatus
+  var path = match[3];
+  var format = match[4];
+  var apiUrl = githubApiUrl + '/repos/' + user + '/' + repo + '/contents/' + path;
+
+  var badgeData = getBadgeData('size', data);
+  if (badgeData.template === 'social') {
+    badgeData.logo = badgeData.logo || logos.github;
+  }
+
+  githubAuth.request(request, apiUrl, {}, function(err, res, buffer) {
+    if (err != null) {
+      badgeData.text[1] = 'inaccessible';
+      sendBadge(format, badgeData);
+      return;
+    }
+    try {
+      if (res.statusCode === 404) {
+        badgeData.text[1] = 'repo or file not found';
+        sendBadge(format, badgeData);
+        return;
+      }
+      var body = JSON.parse(buffer);
+      if (body && Number.isInteger(body.size)) {
+        badgeData.text[1] = prettyBytes(body.size);
+        badgeData.colorscheme = 'green';
+        sendBadge(format, badgeData);
+      } else {
+        badgeData.text[1] = 'not a regular file';
+        sendBadge(format, badgeData);
+      }
+    } catch(e) {
+      badgeData.text[1] = 'invalid';
+      sendBadge(format, badgeData);
+    }
+  });
+}));
+
 // Bitbucket issues integration.
 camp.route(/^\/bitbucket\/issues(-raw)?\/([^\/]+)\/([^\/]+)\.(svg|png|gif|jpg|json)$/,
 cache(function(data, match, sendBadge, request) {
diff --git a/service-tests/github.js b/service-tests/github.js
new file mode 100644
index 0000000000..6bc95aab2c
--- /dev/null
+++ b/service-tests/github.js
@@ -0,0 +1,28 @@
+'use strict';
+
+const Joi = require('joi');
+const ServiceTester = require('./runner/service-tester');
+
+const t = new ServiceTester({ id: 'github', title: 'Github' });
+module.exports = t;
+
+t.create('File size')
+  .get('/size/webcaetano/craft/build/craft.min.js.json')
+  .expectJSONTypes(Joi.object().keys({
+    name: Joi.equal('size'),
+    value: Joi.string().regex(/^[0-9]*[.]?[0-9]+\s(B|kB|MB|GB|TB|PB|EB|ZB|YB)$/),
+  }));
+
+t.create('File size 404')
+  .get('/size/webcaetano/craft/build/does-not-exist.min.js.json')
+  .expectJSONTypes(Joi.object().keys({
+    name: Joi.equal('size'),
+    value: Joi.string().regex(/^repo or file not found$/),
+  }));
+
+t.create('File size for "not a regular file"')
+  .get('/size/webcaetano/craft/build.json')
+  .expectJSONTypes(Joi.object().keys({
+    name: Joi.equal('size'),
+    value: Joi.string().regex(/^not a regular file$/),
+  }));
diff --git a/try.html b/try.html
index 1d48e2b62b..e22a3b4989 100644
--- a/try.html
+++ b/try.html
@@ -798,6 +798,10 @@ Pixel-perfect   Retina-ready   Fast   Consistent   Hackable
     <td><img src='/github/license/mashape/apistatus.svg' alt=''/></td>
     <td><code>https://img.shields.io/github/license/mashape/apistatus.svg</code></td>
   </tr>
+  <tr><th data-keywords='GitHub file size' data-doc='githubDoc'> Github file size: </th>
+    <td><img src='/github/size/webcaetano/craft/build/craft.min.js.svg' alt=''/></td>
+    <td><code>https://img.shields.io/github/size/webcaetano/craft/build/craft.min.js.svg</code></td>
+  </tr>
   <tr><th> Bitbucket issues: </th>
     <td><img src='/bitbucket/issues/atlassian/python-bitbucket.svg' alt=''/></td>
     <td><code>https://img.shields.io/bitbucket/issues/atlassian/python-bitbucket.svg</code></td>