Follow these steps:

1. Click anywhere inside the keyboard area so the page can receive your keystrokes. The status dot turns red when the tester is listening.
2. Press every key on your keyboard. A key turns red while you hold it and gets a green light once it has registered.
3. When every key has its green light, the test is complete and your keyboard has passed.
4. To start over, click Reset test or press Ctrl+Space.

Sizes: 40%, 60%, 65%, 75%, TKL, 96%, full size and a standalone numpad. Layouts: US-ANSI, UK-ISO, DE-ISO, FR-ISO, ES-ISO, IT-ISO, JP-JIS and KR-ANSI.

Leave both on Auto and the tester switches size and layout for you as you press keys. If you would rather choose yourself, pick your size and layout first and untick Auto-switch size & layout.

Yes. Choose the layout that matches the letters printed on your keycaps, for example FR-ISO for AZERTY or DE-ISO for QWERTZ, and the keys on screen show the same legends as yours.

The tester reads the physical position of each key, so the right key lights up whatever language your computer is set to.

A key stays dark when the browser never received a signal from it. Work through these in order:

1. Check that the size and layout match your keyboard. A wrong layout puts keys in the wrong place.
2. Reconnect the keyboard, try another USB port, or check the battery and the wireless connection.
3. Press the key a few more times, firmly and straight down.
4. Try the keyboard on another computer. If the key is still dark, its switch or solder joint may have failed.

Click Show missing keys to see every key that has not sent a signal yet.

The tester flags a key that registers a second press within about 35 milliseconds of being released. That is faster than any finger can press twice, so it points to the switch rather than to you.

The usual cause is a worn or dirty switch contact. Cleaning around the key can help. On a hot-swappable keyboard you can replace just that switch instead of the whole keyboard.

A key stayed pressed for more than 5 seconds. If you were not touching it, the key may be stuck. Let go of every key and check whether the warning clears. If it does not, the key may need cleaning or a new switch.

The Fn key is handled inside the keyboard itself and is never sent to the computer, so no website can detect it. Win, Menu and PrtSc are often taken by the operating system before the page sees them.

Because of this, Win, Menu and PrtSc are optional. They do not count against a pass.

Hold down as many keys as you can. The counter shows the most keys your keyboard reported at the same time.

If you hold eight keys and it shows six, your keyboard limits how many keys it reports together. Keyboards with N-key rollover report every key you press, and some keyboards report fewer in wireless mode.

Browser shortcuts still work while you test. F5 reloads the page, which clears your results, and F11 switches to full screen. The tester still records the key. Press F11 again to leave full screen, and test F5 last.

No. The tester runs entirely in your browser and nothing you type is sent anywhere.