diff --git a/test/keyboard-lock/index.html b/test/keyboard-lock/index.html
new file mode 100755
index 0000000..e1aa7be
--- /dev/null
+++ b/test/keyboard-lock/index.html
@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+  <meta charset="utf-8" />
+  <meta http-equiv="X-UA-Compatible" content="IE=edge" />
+  <script></script>
+  <meta name="viewport" content="width=device-width, initial-scale=1" />
+
+  <title>Keyboard Lock Demo</title>
+
+  <!-- import the webpage's stylesheet -->
+  <link rel="stylesheet" href="./style.css" />
+
+  <!-- import the webpage's javascript file -->
+  <script src="./script.js" defer></script>
+</head>
+
+<body>
+  <main>
+    <h1>Keyboard Lock Demo</h1>
+
+    <p>
+      Press the button to toggle full screen mode.
+      <button id="fullscreen" type="button">Enter full screen</button>
+    </p>
+
+    <div hidden>
+      Press the button to toggle the keyboard lock. When the keyboard lock is
+      active, try pressing <kbd>Command</kbd>&nbsp;+&nbsp;<kbd>T</kbd> (new
+      tab) or <kbd>Command</kbd>&nbsp;+&nbsp;<kbd>N</kbd> (new window). It
+      won't work when the keyboard lock is active.
+      <button id="keyboard" type="button">Activate keyboard lock</button>
+      <div>
+        Hold the <kbd>Esc</kbd> key for two seconds to exit full screen.
+      </div>
+    </div>
+    <div class="info" hidden>
+      The keyboard lock has captured this key or key combination.
+    </div>
+  </main>
+</body>
+
+</html>
\ No newline at end of file
diff --git a/test/keyboard-lock/script.js b/test/keyboard-lock/script.js
new file mode 100755
index 0000000..18e285b
--- /dev/null
+++ b/test/keyboard-lock/script.js
@@ -0,0 +1,83 @@
+if (window.self === window.top) {
+  if (!("keyboard" in navigator)) {
+    alert("Your browser does not support the Keyboard Lock API.");
+  }
+}
+
+const fullscreenButton = document.querySelector("#fullscreen");
+const keyboardButton = document.querySelector("#keyboard");
+const body = document.body;
+const div = document.querySelector("div");
+const info = document.querySelector(".info");
+
+const ENTER_FULLSCREEN = "Enter full screen";
+const LEAVE_FULLSCREEN = "Leave full screen";
+const ACTIVATE_KEYBOARD_LOCK = "Activate keyboard lock";
+const DEACTIVATE_KEYBOARD_LOCK = "Dectivate keyboard lock";
+
+const LOCKED_KEYS = ["MetaLeft", "MetaRight", "Tab", "KeyN", "KeyT", "Escape"];
+
+let lock = false;
+
+fullscreenButton.addEventListener("click", async () => {
+  if (window.self !== window.top) {
+    window.open(location.href, "", "noopener,noreferrer");
+    return;
+  }
+  try {
+    if (!document.fullscreen) {
+      await document.documentElement.requestFullscreen();
+      fullscreenButton.textContent = LEAVE_FULLSCREEN;
+      return;
+    }
+    await document.exitFullscreen();
+    fullscreenButton.textContent = ENTER_FULLSCREEN;
+  } catch (err) {
+    fullscreenButton.textContent = ENTER_FULLSCREEN;
+    alert(`${err.name}: ${err.message}`);
+  }
+});
+
+keyboardButton.addEventListener("click", async () => {
+  try {
+    if (!lock) {
+      //await navigator.keyboard.lock(LOCKED_KEYS);
+      await navigator.keyboard.lock();
+      lock = true;
+      keyboardButton.textContent = DEACTIVATE_KEYBOARD_LOCK;
+      return;
+    }
+    navigator.keyboard.unlock();
+    keyboardButton.textContent = ACTIVATE_KEYBOARD_LOCK;
+    lock = false;
+  } catch (err) {
+    lock = false;
+    keyboardButton.textContent = ACTIVATE_KEYBOARD_LOCK;
+    alert(`${err.name}: ${err.message}`);
+  }
+});
+
+document.addEventListener("fullscreenchange", () => {
+  keyboardButton.textContent = ACTIVATE_KEYBOARD_LOCK;
+  lock = false;
+  if (document.fullscreen) {
+    fullscreenButton.textContent = LEAVE_FULLSCREEN;
+    return (div.style.display = "block");
+  }
+  fullscreenButton.textContent = ENTER_FULLSCREEN;
+  div.style.display = "none";
+});
+
+document.addEventListener("keydown", (e) => {
+  if (
+    lock &&
+    (e.code === "Escape" ||
+      ((e.code === "KeyN" || e.code === "KeyT") &&
+        (event.ctrlKey || event.metaKey)))
+  ) {
+    info.style.display = "block";
+    setTimeout(() => {
+      info.style.display = "none";
+    }, 3000);
+  }
+});
diff --git a/test/keyboard-lock/style.css b/test/keyboard-lock/style.css
new file mode 100755
index 0000000..ffccde4
--- /dev/null
+++ b/test/keyboard-lock/style.css
@@ -0,0 +1,46 @@
+/* CSS files add styling rules to your content */
+
+:root {
+  color-scheme: dark light;
+}
+
+html {
+  display: flex;
+  justify-content: center;
+}
+
+body {
+  font-family: helvetica, arial, sans-serif;
+  margin: 2em;
+}
+
+main {
+  max-width: 500px;
+}
+
+h1 {
+  color: #373fff;
+}
+
+button {
+  display: block;
+  margin-block: 1rem;
+  width: 100%;
+}
+
+p,
+div {
+  margin-block-end: 2.5rem;
+}
+
+kbd {
+  outline: solid 1px gray;
+  background-color: lightgray;
+  color: black;
+  padding-inline: 0.25rem;
+  font-family: monospace;
+}
+
+.info {
+  color: red;
+}
