⌨️ Keyboard Tester
Press any key to see it light up — detect stuck or broken keys instantly
About the Keyboard Tester
The ToolNestr Keyboard Tester is a free, browser-based tool that helps you test every key on your keyboard to verify it registers correctly. Whether you have just purchased a new keyboard, are troubleshooting a key that seems unresponsive, or want to confirm that your existing keyboard is working properly before an important task, this tool provides instant visual feedback with no software to install and no sign-up required.
The tester renders a complete keyboard layout directly in the browser, including the main QWERTY alpha keys, the number row, all function keys (F1–F12), the navigation cluster (Insert, Home, Page Up, Delete, End, Page Down), arrow keys, and the numeric keypad. When you press a key, the corresponding key in the virtual layout highlights in indigo to show it is active, and turns green once released to mark it as successfully tested. A progress counter shows how many unique keys you have tested so far.
Why test your keyboard?
Keyboards can develop problems for several reasons. Mechanical key switches eventually wear out after millions of keystrokes, causing them to register inconsistently or stop registering entirely. Liquid spills can cause keys to stick or short-circuit. Wireless keyboards can drop keystrokes if the battery is low or the receiver is too far away. Gaming keyboards sometimes experience ghosting — the failure to register simultaneous key presses — when the hardware does not support enough simultaneous inputs (referred to as N-key rollover or NKRO).
After cleaning a keyboard or replacing key caps, it is good practice to run a full test to confirm every key works before putting the keyboard back into service. The Keyboard Tester makes this quick and methodical: press every key in order, and any key that does not turn green is one you need to investigate.
Key information panel
When you press a key, the information panel on the right shows the key's display name, its event.key value (the character or action it produces), its event.code value (the physical key identifier that is layout-independent), and its keyCode number (the numeric code used by older JavaScript applications). It also shows which modifier keys — Shift, Ctrl, Alt, and Meta — were held when the key was pressed. This information is useful for developers debugging keyboard shortcut handlers, for understanding the difference between key and code values, and for identifying keys that produce unexpected values on non-standard keyboard layouts.
Mobile and touch devices
On touch devices without a physical keyboard, a notice is displayed explaining that the tester requires a hardware keyboard to function. Mobile on-screen keyboards do not fire the same keyboard events as physical keyboards, and therefore cannot be tested with this tool. If you need to test a keyboard connected to a mobile device via USB or Bluetooth, many such connections do fire the standard keyboard events and should work correctly with this tester.
Browser compatibility and key limitations
The tester works in all modern browsers including Chrome, Firefox, Safari, and Edge. A small number of keys may be captured by the browser or operating system before reaching the page — for example, pressing F5 will reload the page in most browsers, and certain keyboard shortcuts like Ctrl+T or Cmd+Q are handled by the browser. The tester attempts to intercept as many keys as possible, but system-level shortcuts cannot be captured by any web application. If you need to test these keys, consider using a dedicated desktop keyboard testing application instead.