diff --git a/www/index.html b/www/index.html
index 6f1286f5c2..6dacaf75c0 100644
--- a/www/index.html
+++ b/www/index.html
@@ -87,6 +87,29 @@
   <p class="other-platforms-help">You appear to be running Windows 64-bit. If not, <a class="default-platform-button" href="#">display all supported installers</a>.</p>
 </div>
 
+<div id="platform-instructions-win-arm64" class="instructions display-none">
+  <p>
+    To install Rust, download and run
+    <a class="windows-download" href="https://win.rustup.rs/aarch64">rustup&#x2011;init.exe</a>
+    then follow the onscreen instructions.
+  </p>
+  <p>You may also need the <a href="https://rust-lang.github.io/rustup/installation/windows-msvc.html">Visual Studio prerequisites</a>.</p>
+  <hr/>
+  <p>If you're a Windows Subsystem for Linux user run the following in your terminal, then follow the onscreen instructions to install Rust.</p>
+  <div class="copy-container">
+    <pre class="rustup-command">curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh</pre>
+    <button id="copy-button-win-arm64" class="copy-button" title="Copy curl command to clipboard to download Rustup" type="button">
+      <div class="copy-icon">
+        <svg width="24" height="25" viewBox="0 0 24 25" xmlns="http://www.w3.org/2000/svg" alt="Copy curl command to clipboard to download Rustup">
+          <path d="M18 20h2v3c0 1-1 2-2 2H2c-.998 0-2-1-2-2V5c0-.911.755-1.667 1.667-1.667h5A3.323 3.323 0 0110 0a3.323 3.323 0 013.333 3.333h5C19.245 3.333 20 4.09 20 5v8.333h-2V9H2v14h16v-3zM3 7h14c0-.911-.793-1.667-1.75-1.667H13.5c-.957 0-1.75-.755-1.75-1.666C11.75 2.755 10.957 2 10 2s-1.75.755-1.75 1.667c0 .911-.793 1.666-1.75 1.666H4.75C3.793 5.333 3 6.09 3 7z"></path><path d="M4 19h6v2H4zM12 11H4v2h8zM4 17h4v-2H4zM15 15v-3l-4.5 4.5L15 21v-3l8.027-.032L23 15z"></path>
+        </svg>
+      </div>
+      <div id="copy-status-message-win-arm64" class="copy-button-text">Copied!</div>
+    </button>
+  </div>
+  <p class="other-platforms-help">You appear to be running Windows on Arm. If not, <a class="default-platform-button" href="#">display all supported installers</a>.</p>
+</div>
+
 <div id="platform-instructions-unknown" class="instructions display-none">
   <!-- unrecognized platform: ask for help -->
   <p>I don't recognize your platform.</p>
@@ -132,6 +155,16 @@
 
   <hr/>
 
+  <div>
+    <p>
+      If you are running Windows on Arm,<br/>download and run
+      <a class="windows-download" href="https://win.rustup.rs/aarch64">rustup&#x2011;init.exe</a>
+      then follow the onscreen instructions.
+    </p>
+  </div>
+
+  <hr/>
+
   <div>
     <p>
       If you are running Windows 32-bit,<br/>download and run
@@ -171,6 +204,16 @@
 
   <hr/>
 
+  <div>
+    <p>
+      If you are running Windows on Arm,<br/>download and run
+      <a class="windows-download" href="https://win.rustup.rs/aarch64">rustup&#x2011;init.exe</a>
+      then follow the onscreen instructions.
+    </p>
+  </div>
+
+  <hr/>
+
   <div>
     <p>
       If you are running Windows 32-bit,<br/>download and run
diff --git a/www/rustup.css b/www/rustup.css
index d8a32181d5..d3146d8d90 100644
--- a/www/rustup.css
+++ b/www/rustup.css
@@ -108,6 +108,7 @@ hr {
 #platform-instructions-unix > p,
 #platform-instructions-win32 > p,
 #platform-instructions-win64 > p,
+#platform-instructions-win-arm64 > p,
 #platform-instructions-default > p,
 #platform-instructions-unknown > p {
     width: 40rem;
@@ -138,6 +139,7 @@ hr {
 #platform-instructions-unix div.copy-container,
 #platform-instructions-win32 div.copy-container,
 #platform-instructions-win64 div.copy-container,
+#platform-instructions-win-arm64 div.copy-container,
 #platform-instructions-default div.copy-container,
 #platform-instructions-unknown div.copy-container {
     display: flex;
@@ -147,6 +149,7 @@ hr {
 #platform-instructions-unix button.copy-button,
 #platform-instructions-win32 button.copy-button,
 #platform-instructions-win64 button.copy-button,
+#platform-instructions-win-arm64 button.copy-button,
 #platform-instructions-default button.copy-button,
 #platform-instructions-unknown button.copy-button {
     height: 58px;
@@ -160,6 +163,7 @@ hr {
 #platform-instructions-unix div.copy-icon,
 #platform-instructions-win32 div.copy-icon,
 #platform-instructions-win64 div.copy-icon,
+#platform-instructions-win-arm64 div.copy-icon,
 #platform-instructions-default div.copy-icon,
 #platform-instructions-unknown div.copy-icon {
     position: relative;
@@ -173,6 +177,7 @@ hr {
 #platform-instructions-unix div.copy-button-text,
 #platform-instructions-win32 div.copy-button-text,
 #platform-instructions-win64 div.copy-button-text,
+#platform-instructions-win-arm64 div.copy-button-text,
 #platform-instructions-default div.copy-button-text,
 #platform-instructions-unknown div.copy-button-text {
     transition: opacity 0.2s ease-in-out;
@@ -187,6 +192,7 @@ hr {
 
 #platform-instructions-win32 a.windows-download,
 #platform-instructions-win64 a.windows-download,
+#platform-instructions-win-arm64 a.windows-download,
 #platform-instructions-default a.windows-download,
 #platform-instructions-unknown a.windows-download {
     display: block;
diff --git a/www/rustup.js b/www/rustup.js
index 86558782d5..20d3e7f7c5 100644
--- a/www/rustup.js
+++ b/www/rustup.js
@@ -1,10 +1,10 @@
 // IF YOU CHANGE THIS FILE IT MUST BE CHANGED ON BOTH rust-www and rustup.rs
 
-var platforms = ["default", "unknown", "win32", "win64", "unix"];
+var platforms = ["default", "unknown", "win32", "win64", "win-arm64", "unix"];
 var platform_override = null;
 var rustup_install_command = "curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh";
 
-function detect_platform() {
+async function detect_platform() {
     "use strict";
 
     if (platform_override !== null) {
@@ -29,6 +29,10 @@ function detect_platform() {
     if (navigator.platform == "Win64" ||
         navigator.userAgent.indexOf("WOW64") != -1 ||
         navigator.userAgent.indexOf("Win64") != -1) { os = "win64"; }
+    if (navigator.userAgentData &&
+        navigator.userAgentData.platform == "Windows" &&
+        await navigator.userAgentData.getHighEntropyValues(["architecture", "bitness"])
+            .then(ua => ua.architecture == "arm" && ua.bitness == "64")) { os = "win-arm64"; }
     if (navigator.platform == "FreeBSD x86_64") {os = "unix";}
     if (navigator.platform == "FreeBSD amd64") {os = "unix";}
     if (navigator.platform == "NetBSD x86_64") {os = "unix";}
@@ -68,10 +72,10 @@ function vis(elem, value) {
     }
 }
 
-function adjust_for_platform() {
+async function adjust_for_platform() {
     "use strict";
 
-    var platform = detect_platform();
+    var platform = await detect_platform();
 
     platforms.forEach(function (platform_elem) {
         var platform_div = document.getElementById("platform-instructions-" + platform_elem);
@@ -94,7 +98,7 @@ function adjust_platform_specific_instrs(platform) {
         if (el_is_inline) {
             el_visible_style = "inline";
         }
-        if (platform == "win64" || platform == "win32") {
+        if (platform == "win64" || platform == "win32" || platform == "win-arm64") {
             if (el_is_not_win) {
                 vis(el, "none");
             } else {
@@ -110,13 +114,13 @@ function adjust_platform_specific_instrs(platform) {
     }
 }
 
-function cycle_platform() {
+async function cycle_platform() {
     if (platform_override == null) {
         platform_override = 0;
     } else {
         platform_override = (platform_override + 1) % platforms.length;
     }
-    adjust_for_platform();
+    await adjust_for_platform();
 }
 
 function set_up_cycle_button() {
@@ -127,9 +131,9 @@ function set_up_cycle_button() {
     var idx=0;
     var unlocked=false;
 
-    document.onkeypress = function(event) {
+    document.onkeypress = async function(event) {
         if (event.key == "n" && unlocked) {
-            cycle_platform();
+            await cycle_platform();
         }
 
         if (event.key == key[idx]) {
@@ -138,7 +142,7 @@ function set_up_cycle_button() {
             if (idx == key.length) {
                 vis(cycle_button, "block");
                 unlocked = true;
-                cycle_platform();
+                await cycle_platform();
             }
         } else if (event.key == key[0]) {
             idx = 1;
@@ -148,9 +152,9 @@ function set_up_cycle_button() {
     };
 }
 
-function go_to_default_platform() {
+async function go_to_default_platform() {
     platform_override = 0;
-    adjust_for_platform();
+    await adjust_for_platform();
 }
 
 // NB: This has no effect on rust-lang.org/install.html
@@ -190,6 +194,9 @@ function handle_copy_button_click(e) {
         case 'copy-button-win64':
             process_copy_button_click('copy-status-message-win64');
             break;
+        case 'copy-button-win-arm64':
+            process_copy_button_click('copy-status-message-win-arm64');
+            break;
         case 'copy-button-unknown':
             process_copy_button_click('copy-status-message-unknown');
             break;
@@ -208,8 +215,8 @@ function set_up_copy_button_clicks() {
     })
 }
 
-(function () {
-    adjust_for_platform();
+(async function () {
+    await adjust_for_platform();
     set_up_cycle_button();
     set_up_default_platform_buttons();
     set_up_copy_button_clicks();