Keyboard Layout Tester - Online Visual Key Press Viewer

A keyboard layout tester is an online tool that visually displays which keys you press on your physical keyboard in real-time. It helps you verify that all your keys are functioning correctly, test key combinations, and understand key codes (like event.code and event.key). It's especially useful for diagnosing faulty keys, testing new keyboards, or learning keyboard layouts.

Simply open this page and start pressing keys on your physical keyboard. Each key you press will light up on the visual keyboard layout above. The tool tracks which keys are currently held down, displays detailed information about the last key pressed (including key, code, and keyCode values), and maintains a history of recent keystrokes. On mobile devices, you can use the text input field or connect a Bluetooth keyboard.

Certain keys have special behavior at the operating system level and may not be fully captured by browsers. These include the Print Screen key (often intercepted by the OS for screenshots), Fn keys on laptops (handled by firmware), and some media keys. Additionally, keys like F5, F11, or F12 may trigger browser actions (refresh, fullscreen, developer tools) — this tool tries to prevent those defaults, but some combinations (like Ctrl+W to close a tab) cannot be fully overridden for security reasons. If a key doesn't register here, it may still be functioning normally at the system level.

Yes! This tool tracks all modifier keys (Ctrl, Alt, Shift, Meta/Windows) and shows them as active when held down. When you press a combination like Ctrl+C, you'll see both the Ctrl key and the C key light up simultaneously. The modifier status indicators above the keyboard also update in real-time. Note that some system-level combinations (like Alt+Tab or Ctrl+Alt+Delete) are intercepted by the operating system and may not be fully displayed.

Yes, with some limitations. On mobile devices, the on-screen virtual keyboard may not trigger the same keydown events as a physical keyboard. We provide a text input field for mobile users to test their typing. However, if you connect an external Bluetooth keyboard to your phone or tablet, all keys should be detected normally, just like on a desktop. The visual keyboard layout is fully responsive and scrollable on smaller screens.

• event.key — The character produced by the key (e.g., "a", "A", "ArrowUp"). Affected by Shift, Caps Lock, and keyboard layout.
• event.code — The physical key location on the keyboard (e.g., "KeyA", "ShiftLeft"). This is layout-independent and best for testing physical keys.
• event.keyCode — A numeric code (deprecated but still widely used). E.g., 65 for 'A'. Avoid for new development; use event.code instead.

This tool displays all three values so you can understand each key's properties.

Use this tester to systematically press every key on your keyboard. Watch for keys that: (a) don't light up at all when pressed, (b) require excessive force to register, (c) register multiple times with a single press (key chatter), or (d) get stuck in the "pressed" state after you release them. The total counter helps track consistency — if you press every key once and the count doesn't match, something is wrong. For deeper testing, try N-key rollover tests by holding multiple keys simultaneously.

The visual keyboard shown is the standard ANSI QWERTY layout (common in the US and many English-speaking countries). If you use a different layout (such as ISO, AZERTY, QWERTZ, Dvorak, or Colemak), the physical key positions will still highlight correctly based on event.code, but the labels on the visual keyboard won't match your layout's key output. The tool is still fully functional for testing physical key function regardless of your layout — only the visual labels may differ.

Absolutely. This tool can display multiple simultaneously held keys, making it useful for basic N-key rollover (NKRO) testing. Hold down several keys at once (e.g., W+A+S+D for gaming) and observe whether all of them light up. The "Holding" counter shows how many keys are currently pressed. Note that USB HID limits and browser event handling may impose practical limits — for professional NKRO verification, dedicated hardware-level testing tools are recommended.

This tool works on all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. It uses the standard KeyboardEvent API (keydown and keyup events) which is supported across all major browsers. For the best experience, use an up-to-date browser version. The sound feedback feature uses the Web Audio API, which is also widely supported.