diff --git a/README.md b/README.md
index 46afd50c8e9..e85164e11f8 100644
--- a/README.md
+++ b/README.md
@@ -43,7 +43,7 @@ See the following examples for more detail on bundling OpenLayers with your appl
 
 ## Supported Browsers
 
-OpenLayers runs on all modern browsers that support [HTML5](https://html.spec.whatwg.org/multipage/) and [ECMAScript 5](http://www.ecma-international.org/ecma-262/5.1/). This includes Chrome, Firefox, Safari and Edge. For older browsers and platforms like Internet Explorer (down to version 9) and Android 4.x, [polyfills](http://polyfill.io) for `requestAnimationFrame` and `Element.prototype.classList` are required, and using the KML format requires a polyfill for `URL`.
+OpenLayers runs on all modern browsers that support [HTML5](https://html.spec.whatwg.org/multipage/) and [ECMAScript 5](http://www.ecma-international.org/ecma-262/5.1/). This includes Chrome, Firefox, Safari and Edge. For older browsers and platforms like Internet Explorer (down to version 9) and Android 4.x, [polyfills](https://cdnjs.cloudflare.com/polyfill) for `requestAnimationFrame` and `Element.prototype.classList` are required, and using the KML format requires a polyfill for `URL`.
 
 ## Documentation
 
diff --git a/config/jsdoc/api/template/tmpl/layout.tmpl b/config/jsdoc/api/template/tmpl/layout.tmpl
index fd99c511a70..0cd2546583d 100644
--- a/config/jsdoc/api/template/tmpl/layout.tmpl
+++ b/config/jsdoc/api/template/tmpl/layout.tmpl
@@ -13,7 +13,7 @@ var version = obj.packageInfo.version;
     </script>
     <meta charset="utf-8">
     <title>OpenLayers v<?js= version ?> API - <?js= title ?></title>
-    <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=fetch"></script>
+    <script src="https://cdnjs.cloudflare.com/polyfill/v2/polyfill.min.js?features=fetch"></script>
     <script src="scripts/prettify/prettify.js"> </script>
     <script src="scripts/prettify/lang-css.js"> </script>
     <script src="scripts/jquery.min.js"> </script>
diff --git a/doc/quickstart.hbs b/doc/quickstart.hbs
index 13edbfbda57..5eafeb25b5e 100644
--- a/doc/quickstart.hbs
+++ b/doc/quickstart.hbs
@@ -68,7 +68,7 @@ The first part is to include the JavaScript library. For the purpose of this tut
 **Optional:** If the application is intended to run on old platforms like Internet Explorer or Android 4.x, another script needs to be included before OpenLayers:
 
 ```xml
-  <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList"></script>
+  <script src="https://cdnjs.cloudflare.com/polyfill/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList"></script>
 ```
 
 
diff --git a/doc/tutorials/background.md b/doc/tutorials/background.md
index 4324c900fe9..9094ecd7696 100644
--- a/doc/tutorials/background.md
+++ b/doc/tutorials/background.md
@@ -19,7 +19,7 @@ OpenLayers is available as [`ol` npm package](https://npmjs.com/package/ol), whi
 
 By default, OpenLayers uses a performance optimized Canvas renderer. An experimental WebGL renderer (without text rendering support) is also available.
 
-OpenLayers runs on all modern browsers that support [HTML5](https://html.spec.whatwg.org/multipage/) and [ECMAScript 5](http://www.ecma-international.org/ecma-262/5.1/). This includes Chrome, Firefox, Safari and Edge. For older browsers and platforms like Internet Explorer (down to version 9) and Android 4.x, [polyfills](http://polyfill.io), the application bundle needs to be transpiled (e.g. using [Babel](https://babeljs.io)) and bundled with polyfills for `requestAnimationFrame`, `Element.prototype.classList` and `URL`.
+OpenLayers runs on all modern browsers that support [HTML5](https://html.spec.whatwg.org/multipage/) and [ECMAScript 5](http://www.ecma-international.org/ecma-262/5.1/). This includes Chrome, Firefox, Safari and Edge. For older browsers and platforms like Internet Explorer (down to version 9) and Android 4.x, [polyfills](https://cdnjs.cloudflare.com/polyfill), the application bundle needs to be transpiled (e.g. using [Babel](https://babeljs.io)) and bundled with polyfills for `requestAnimationFrame`, `Element.prototype.classList` and `URL`.
 
 The library is intended for use on both desktop/laptop and mobile devices, and supports pointer and touch interactions.
 
diff --git a/examples/templates/example.html b/examples/templates/example.html
index ac807473a8c..7252d51e455 100644
--- a/examples/templates/example.html
+++ b/examples/templates/example.html
@@ -18,7 +18,7 @@
     <link rel="stylesheet" href="./resources/layout.css" type="text/css">
     {{{ extraHead.local }}}
     {{{ css.tag }}}
-    <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=fetch,requestAnimationFrame,Element.prototype.classList,URL"></script>
+    <script src="https://cdnjs.cloudflare.com/polyfill/v2/polyfill.min.js?features=fetch,requestAnimationFrame,Element.prototype.classList,URL"></script>
     <script src="https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/1.7.1/clipboard.min.js"></script>
     <title>{{ title }}</title>
   </head>
@@ -81,7 +81,7 @@ <h4 id="title">{{ title }}</h4>
     &lt;title&gt;{{ title }}&lt;/title&gt;
     &lt;link rel="stylesheet" href="https://openlayers.org/en/v{{ olVersion }}/css/ol.css" type="text/css"&gt;
     &lt;!-- The line below is only needed for old environments like Internet Explorer and Android 4.x --&gt;
-    &lt;script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"&gt;&lt;/script&gt;
+    &lt;script src="https://cdnjs.cloudflare.com/polyfill/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"&gt;&lt;/script&gt;
     {{#if extraHead.remote}}
 {{ indent extraHead.remote spaces=4 }}{{/if}}{{#if css.source}}
     &lt;style&gt;
diff --git a/examples/vector-label-decluttering.html b/examples/vector-label-decluttering.html
index 9bbc13b512f..aa15cbd5f1e 100644
--- a/examples/vector-label-decluttering.html
+++ b/examples/vector-label-decluttering.html
@@ -3,7 +3,7 @@
 title: Vector Label Decluttering
 shortdesc: Label decluttering with a custom renderer.
 resources:
-  - https://cdn.polyfill.io/v2/polyfill.min.js?features=Set"
+  - https://cdnjs.cloudflare.com/polyfill/v2/polyfill.min.js?features=Set"
 docs: >
   Decluttering is used to avoid overlapping labels with `overflow: true` set on the text style. For MultiPolygon geometries, only the widest polygon is selected in a custom `geometry` function.
 tags: "vector, decluttering, labels"