diff --git a/package.json b/package.json
--- a/package.json
+++ b/package.json
@@ -71,6 +71,7 @@
     "cypress": "^4.12.0",
     "cypress-multi-reporters": "^1.4.0",
     "ejs": "^3.1.3",
+    "ejs-compiled-loader": "^3.0.0",
     "eslint": "^7.6.0",
     "eslint-loader": "^4.0.2",
     "eslint-plugin-chai-friendly": "^0.6.0",
diff --git a/swh/web/assets/config/webpack.config.development.js b/swh/web/assets/config/webpack.config.development.js
--- a/swh/web/assets/config/webpack.config.development.js
+++ b/swh/web/assets/config/webpack.config.development.js
@@ -197,6 +197,18 @@
             }
           }]
       },
+      {
+        test: /\.ejs$/,
+        use: [{
+          loader: 'ejs-compiled-loader',
+          options: {
+            htmlmin: true,
+            htmlminOptions: {
+              removeComments: true
+            }
+          }
+        }]
+      },
       // expose jquery to the global context as $ and jQuery when importing it
       {
         test: require.resolve('jquery'),
diff --git a/swh/web/assets/src/bundles/revision/diff-panel.ejs b/swh/web/assets/src/bundles/revision/diff-panel.ejs
new file mode 100644
--- /dev/null
+++ b/swh/web/assets/src/bundles/revision/diff-panel.ejs
@@ -0,0 +1,50 @@
+<%#
+  Copyright (C) 2020  The Software Heritage developers
+  See the AUTHORS file at the top-level directory of this distribution
+  License: GNU Affero General Public License version 3, or any later version
+  See top-level LICENSE file for more information
+%>
+<div id="diff_<%= diffData.id %>" class="card swh-file-diff-panel">
+  <div class="card-header bg-gray-light border-bottom-0">
+    <a data-toggle="collapse" href="#diff_<%= diffData.id %>_content">
+      <div class="float-left swh-title-color">
+        <strong><%= diffPanelTitle %></strong>
+      </div>
+    </a>
+    <div class="ml-auto float-right">
+      <div class="btn-group btn-group-toggle diff-styles"
+           data-toggle="buttons" style="visibility: hidden;">
+        <label class="btn btn-default btn-sm form-check-label active unified-diff-button"
+               onclick="swh.revision.showUnifiedDiff('<%= diffData.id %>')">
+          <input type="radio" name="diffs-switch" id="unified"
+                 autocomplete="off" checked> Unified
+        </label>
+        <label class="btn btn-default btn-sm form-check-label split-diff-button"
+               onclick="swh.revision.showSplitDiff('<%= diffData.id %>')">
+          <input type="radio" name="diffs-switch" id="side-by-side"
+                 autocomplete="off"> Side-by-side
+        </label>
+      </div>
+      <a href="<%= diffData.content_url %>" class="btn btn-default btn-sm"
+         role="button">View file</a>
+    </div>
+    <div class="clearfix"></div>
+  </div>
+  <div id="diff_<%= diffData.id %>_content" class="collapse show">
+    <div class="swh-diff-loading text-center" id="<%= diffData.id %>-loading"
+         style="visibility: hidden;">
+      <img src=<%= swhSpinnerSrc %>>
+      <p>Loading diff ...</p>
+    </div>
+    <div class="highlightjs swh-content" style="display: none;"
+         id="<%= diffData.id %>-highlightjs">
+      <div id="<%= diffData.id %>-unified-diff">
+        <pre><code class="<%= diffData.id %>" id="<%= diffData.id %>"></code></pre>
+      </div>
+      <div style="width: 100%; display: none;" id="<%= diffData.id %>-split-diff">
+        <pre class="float-left" style="width: 50%;"><code class="<%= diffData.id %>" id="<%= diffData.id %>-from"></code></pre>
+        <pre style="width: 50%;"><code class="<%= diffData.id %>" id="<%= diffData.id %>-to"></code></pre>
+      </div>
+    </div>
+  </div>
+</div>
\ No newline at end of file
diff --git a/swh/web/assets/src/bundles/revision/diff-utils.js b/swh/web/assets/src/bundles/revision/diff-utils.js
--- a/swh/web/assets/src/bundles/revision/diff-utils.js
+++ b/swh/web/assets/src/bundles/revision/diff-utils.js
@@ -9,6 +9,8 @@
 
 import {swhSpinnerSrc} from 'utils/constants';
 
+import diffPanelTemplate from './diff-panel.ejs';
+
 // number of changed files in the revision
 let changes = null;
 let nbChangedFiles = 0;
@@ -570,44 +572,11 @@
   if (diffData.type === 'rename') {
     diffPanelTitle = `${diffData.from_path} &rarr; ${diffData.to_path}`;
   }
-  let diffPanelHtml =
-  `<div id="diff_${diffData.id}" class="card swh-file-diff-panel">
-    <div class="card-header bg-gray-light border-bottom-0">
-      <a data-toggle="collapse" href="#diff_${diffData.id}_content">
-        <div class="float-left swh-title-color">
-          <strong>${diffPanelTitle}</strong>
-        </div>
-      </a>
-      <div class="ml-auto float-right">
-        <div class="btn-group btn-group-toggle diff-styles" data-toggle="buttons" style="visibility: hidden;">
-          <label class="btn btn-default btn-sm form-check-label active unified-diff-button" onclick="swh.revision.showUnifiedDiff('${diffData.id}')">
-            <input type="radio" name="diffs-switch" id="unified" autocomplete="off" checked> Unified
-          </label>
-          <label class="btn btn-default btn-sm form-check-label split-diff-button" onclick="swh.revision.showSplitDiff('${diffData.id}')">
-            <input type="radio" name="diffs-switch" id="side-by-side" autocomplete="off"> Side-by-side
-          </label>
-        </div>
-        <a href="${diffData.content_url}" class="btn btn-default btn-sm" role="button">View file</a>
-      </div>
-      <div class="clearfix"></div>
-    </div>
-    <div id="diff_${diffData.id}_content" class="collapse show">
-      <div class="swh-diff-loading text-center" id="${diffData.id}-loading" style="visibility: hidden;">
-        <img src=${swhSpinnerSrc}></img>
-        <p>Loading diff ...</p>
-      </div>
-      <div class="highlightjs swh-content" style="display: none;" id="${diffData.id}-highlightjs">
-        <div id="${diffData.id}-unified-diff">
-          <pre><code class="${diffData.id}" id="${diffData.id}"></code></pre>
-        </div>
-        <div style="width: 100%; display: none;" id="${diffData.id}-split-diff">
-          <pre class="float-left" style="width: 50%;"><code class="${diffData.id}" id="${diffData.id}-from"></code></pre>
-          <pre style="width: 50%"><code class="${diffData.id}" id="${diffData.id}-to"></code></pre>
-        </div>
-      </div>
-    </div>
-  </div>`;
-  return diffPanelHtml;
+  return diffPanelTemplate({
+    diffData: diffData,
+    diffPanelTitle: diffPanelTitle,
+    swhSpinnerSrc: swhSpinnerSrc
+  });
 }
 
 // setup waypoints to request diffs computation on the fly while scrolling
diff --git a/yarn.lock b/yarn.lock
--- a/yarn.lock
+++ b/yarn.lock
@@ -3611,6 +3611,14 @@
   resolved "https://registry.yarnpkg.com/callsites/-/callsites-3.1.0.tgz#b3630abd8943432f54b3f0519238e33cd7df2f73"
   integrity sha512-P8BjAsXvZS+VIDUI11hHCQEv74YT67YUi5JJFNWIqL235sBmjX4+qx9Muvls5ivyNENctx46xQLQ3aTuE7ssaQ==
 
+camel-case@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/camel-case/-/camel-case-3.0.0.tgz#ca3c3688a4e9cf3a4cda777dc4dcbc713249cf73"
+  integrity sha1-yjw2iKTpzzpM2nd9xNy8cTJJz3M=
+  dependencies:
+    no-case "^2.2.0"
+    upper-case "^1.1.1"
+
 camelcase-keys@^2.0.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/camelcase-keys/-/camelcase-keys-2.1.0.tgz#308beeaffdf28119051efa1d932213c91b8f92e7"
@@ -3879,6 +3887,13 @@
     isobject "^3.0.0"
     static-extend "^0.1.1"
 
+clean-css@^4.2.1:
+  version "4.2.3"
+  resolved "https://registry.yarnpkg.com/clean-css/-/clean-css-4.2.3.tgz#507b5de7d97b48ee53d84adb0160ff6216380f78"
+  integrity sha512-VcMWDN54ZN/DS+g58HYL5/n4Zrqe8vHJpGA8KdgUXFU4fuP/aHNw8eld9SyEIyabIMJX/0RaY/fplOo5hYLSFA==
+  dependencies:
+    source-map "~0.6.0"
+
 clean-stack@^2.0.0:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/clean-stack/-/clean-stack-2.2.0.tgz#ee8472dbb129e727b31e8a10a427dee9dfe4008b"
@@ -4094,7 +4109,7 @@
   dependencies:
     delayed-stream "~1.0.0"
 
-commander@2, commander@^2.20.0:
+commander@2, commander@^2.19.0, commander@^2.20.0:
   version "2.20.3"
   resolved "https://registry.yarnpkg.com/commander/-/commander-2.20.3.tgz#fd485e84c03eb4881c20722ba48035e8531aeb33"
   integrity sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ==
@@ -5552,6 +5567,22 @@
   resolved "https://registry.yarnpkg.com/ee-first/-/ee-first-1.1.1.tgz#590c61156b0ae2f4f0255732a158b266bc56b21d"
   integrity sha1-WQxhFWsK4vTwJVcyoViyZrxWsh0=
 
+ejs-compiled-loader@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/ejs-compiled-loader/-/ejs-compiled-loader-3.0.0.tgz#a425b07f436d1bb2ad6f47e0fbfbb6b829d684b9"
+  integrity sha512-AR2y2TB2CdBO4cxSo2ZEqClL61NKgWa1fbB+r7z0MnC6pPjcSJgNL9ylMpDI/Olt1lAGifWw3ElX/t+x69RJUg==
+  dependencies:
+    ejs "^2"
+    html-minifier "^4"
+    loader-utils "^2"
+    merge "^1.2.1"
+    terser "^4.6"
+
+ejs@^2:
+  version "2.7.4"
+  resolved "https://registry.yarnpkg.com/ejs/-/ejs-2.7.4.tgz#48661287573dcc53e366c7a1ae52c3a120eec9ba"
+  integrity sha512-7vmuyh5+kuUyJKePhQfRQBhXV5Ce+RnaeeQArKu1EAMpL3WbgMt5WG6uQZpEVvYSSsxMXRKOewtDk9RaTKXRlA==
+
 ejs@^3.1.3:
   version "3.1.3"
   resolved "https://registry.yarnpkg.com/ejs/-/ejs-3.1.3.tgz#514d967a8894084d18d3d47bd169a1c0560f093d"
@@ -7181,7 +7212,7 @@
     is-stream "^2.0.0"
     type-fest "^0.8.0"
 
-he@1.2.0, he@^1.1.0:
+he@1.2.0, he@^1.1.0, he@^1.2.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/he/-/he-1.2.0.tgz#84ae65fa7eafb165fddb61566ae14baf05664f0f"
   integrity sha512-F/1DnUGPopORZi0ni+CvrCgHQ5FyEAHRLSApuYWMmrbSwoN2Mn/7k+Gl38gJnR7yyDZk6WLXwiGod1JOWNDKGw==
@@ -7280,6 +7311,19 @@
   resolved "https://registry.yarnpkg.com/html-escaper/-/html-escaper-2.0.2.tgz#dfd60027da36a36dfcbe236262c00a5822681453"
   integrity sha512-H2iMtd0I4Mt5eYiapRdIDjp+XzelXQ0tFE4JS7YFwFevXXMmOp9myNrUvCg0D6ws8iqkRPBfKHgbwig1SmlLfg==
 
+html-minifier@^4:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/html-minifier/-/html-minifier-4.0.0.tgz#cca9aad8bce1175e02e17a8c33e46d8988889f56"
+  integrity sha512-aoGxanpFPLg7MkIl/DDFYtb0iWz7jMFGqFhvEDZga6/4QTjneiD8I/NXL1x5aaoCp7FSIT6h/OhykDdPsbtMig==
+  dependencies:
+    camel-case "^3.0.0"
+    clean-css "^4.2.1"
+    commander "^2.19.0"
+    he "^1.2.0"
+    param-case "^2.1.1"
+    relateurl "^0.2.7"
+    uglify-js "^3.5.1"
+
 html-tags@^3.1.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/html-tags/-/html-tags-3.1.0.tgz#7b5e6f7e665e9fb41f30007ed9e0d41e97fb2140"
@@ -8693,7 +8737,7 @@
     emojis-list "^3.0.0"
     json5 "^1.0.1"
 
-loader-utils@^2.0.0:
+loader-utils@^2, loader-utils@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/loader-utils/-/loader-utils-2.0.0.tgz#e4cace5b816d425a166b5f097e10cd12b36064b0"
   integrity sha512-rP4F0h2RaWSvPEkD7BLDFQnvSf+nK+wr3ESUjNTyAGobqrijmW92zc+SO6d4p4B1wh7+B/Jg1mkQe5NYUEHtHQ==
@@ -8852,6 +8896,11 @@
     currently-unhandled "^0.4.1"
     signal-exit "^3.0.0"
 
+lower-case@^1.1.1:
+  version "1.1.4"
+  resolved "https://registry.yarnpkg.com/lower-case/-/lower-case-1.1.4.tgz#9a2cabd1b9e8e0ae993a4bf7d5875c39c42e8eac"
+  integrity sha1-miyr0bno4K6ZOkv31YdcOcQujqw=
+
 lowercase-keys@^1.0.0, lowercase-keys@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/lowercase-keys/-/lowercase-keys-1.0.1.tgz#6f9e30b47084d971a7c820ff15a6c5167b74c26f"
@@ -9106,6 +9155,11 @@
   resolved "https://registry.yarnpkg.com/merge2/-/merge2-1.3.0.tgz#5b366ee83b2f1582c48f87e47cf1a9352103ca81"
   integrity sha512-2j4DAdlBOkiSZIsaXk4mTE3sRS02yBHAtfy127xRV3bQUFqXkjHCHLW6Scv7DwNRbIWNHH8zpnz9zMaKXIdvYw==
 
+merge@^1.2.1:
+  version "1.2.1"
+  resolved "https://registry.yarnpkg.com/merge/-/merge-1.2.1.tgz#38bebf80c3220a8a487b6fcfb3941bb11720c145"
+  integrity sha512-VjFo4P5Whtj4vsLzsYBu5ayHhoHJ0UqNm7ibvShmbmoz7tGi0vXaoJbGdB+GmDMLUdg8DpQXEIeVDAe8MaABvQ==
+
 methods@~1.1.2:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/methods/-/methods-1.1.2.tgz#5529a4d67654134edcc5266656835b0f851afcee"
@@ -9557,6 +9611,13 @@
   resolved "https://registry.yarnpkg.com/nice-try/-/nice-try-1.0.5.tgz#a3378a7696ce7d223e88fc9b764bd7ef1089e366"
   integrity sha512-1nh45deeb5olNY7eX82BkPO7SSxR5SSYJiPTrTdFUVYwAl8CKMA5N9PjTYkHiRjisVcxcQ1HXdLhx2qxxJzLNQ==
 
+no-case@^2.2.0:
+  version "2.3.2"
+  resolved "https://registry.yarnpkg.com/no-case/-/no-case-2.3.2.tgz#60b813396be39b3f1288a4c1ed5d1e7d28b464ac"
+  integrity sha512-rmTZ9kz+f3rCvK2TD1Ue/oZlns7OGoIWP4fc3llxxRXlOkHKoWPPWJOfFYpITabSow43QJbRIoHQXtt10VldyQ==
+  dependencies:
+    lower-case "^1.1.1"
+
 node-alias@^1.0.4:
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/node-alias/-/node-alias-1.0.4.tgz#1f1b916b56b9ea241c0135f97ced6940f556f292"
@@ -10308,6 +10369,13 @@
     inherits "^2.0.3"
     readable-stream "^2.1.5"
 
+param-case@^2.1.1:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/param-case/-/param-case-2.1.1.tgz#df94fd8cf6531ecf75e6bef9a0858fbc72be2247"
+  integrity sha1-35T9jPZTHs915r75oIWPvHK+Ikc=
+  dependencies:
+    no-case "^2.2.0"
+
 parent-module@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/parent-module/-/parent-module-1.0.1.tgz#691d2709e78c79fae3a156622452d00762caaaa2"
@@ -11590,6 +11658,11 @@
   dependencies:
     jsesc "~0.5.0"
 
+relateurl@^0.2.7:
+  version "0.2.7"
+  resolved "https://registry.yarnpkg.com/relateurl/-/relateurl-0.2.7.tgz#54dbf377e51440aca90a4cd274600d3ff2d888a9"
+  integrity sha1-VNvzd+UUQKypCkzSdGANP/LYiKk=
+
 release-zalgo@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/release-zalgo/-/release-zalgo-1.0.0.tgz#09700b7e5074329739330e535c5a90fb67851730"
@@ -12470,7 +12543,7 @@
   resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.5.0.tgz#0fe96503ac86a5adb5de63f4e412ae4872cdbe86"
   integrity sha1-D+llA6yGpa213mP05BKuSHLNvoY=
 
-source-map@0.6.1, source-map@^0.6.0, source-map@^0.6.1, source-map@~0.6.1:
+source-map@0.6.1, source-map@^0.6.0, source-map@^0.6.1, source-map@~0.6.0, source-map@~0.6.1:
   version "0.6.1"
   resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.6.1.tgz#74722af32e9614e9c287a8d0bbde48b5e2f1a263"
   integrity sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==
@@ -13250,7 +13323,7 @@
     source-map "~0.6.1"
     source-map-support "~0.5.12"
 
-terser@^4.8.0:
+terser@^4.6, terser@^4.8.0:
   version "4.8.0"
   resolved "https://registry.yarnpkg.com/terser/-/terser-4.8.0.tgz#63056343d7c70bb29f3af665865a46fe03a0df17"
   integrity sha512-EAPipTNeWsb/3wLPeup1tVPaXfIaU68xMnVdPafIL1TV05OhASArYyIfFvnvJCNrR2NIOvDVNNTFRa+Re2MWyw==
@@ -13560,6 +13633,11 @@
   resolved "https://registry.yarnpkg.com/typeface-alegreya/-/typeface-alegreya-0.0.69.tgz#92d82f3e68360d5d5cee01be812f5aeb19ade8a7"
   integrity sha512-02wj0QZEaxnDH37ZX3fsCu6vlKdaH8f1bzJxuymXNCoEcN3tFKMLC9omAtx8G+EbChb1gm5Nw+9XmPIYzi93fA==
 
+uglify-js@^3.5.1:
+  version "3.10.1"
+  resolved "https://registry.yarnpkg.com/uglify-js/-/uglify-js-3.10.1.tgz#dd14767eb7150de97f2573a5ff210db14fffe4ad"
+  integrity sha512-RjxApKkrPJB6kjJxQS3iZlf///REXWYxYJxO/MpmlQzVkDWVI3PSnCBWezMecmTU/TRkNxrl8bmsfFQCp+LO+Q==
+
 umd@^3.0.0:
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/umd/-/umd-3.0.3.tgz#aa9fe653c42b9097678489c01000acb69f0b26cf"
@@ -13799,6 +13877,11 @@
     semver-diff "^3.1.1"
     xdg-basedir "^4.0.0"
 
+upper-case@^1.1.1:
+  version "1.1.3"
+  resolved "https://registry.yarnpkg.com/upper-case/-/upper-case-1.1.3.tgz#f6b4501c2ec4cdd26ba78be7222961de77621598"
+  integrity sha1-9rRQHC7EzdJrp4vnIilh3ndiFZg=
+
 uri-js@^4.2.2:
   version "4.2.2"
   resolved "https://registry.yarnpkg.com/uri-js/-/uri-js-4.2.2.tgz#94c540e1ff772956e2299507c010aea6c8838eb0"