It's completely free and runs in your browser. There's nothing to download, and no account is needed.

No. Every test runs locally in your browser. Nothing you press is stored or sent anywhere.

Yes. Leave the size on Auto and start typing. Every key that works lights up, and the layout switches by itself when the tester spots an ISO, JIS or Korean key. For 40%, 96%, Alice, split or other custom boards, pick the closest size and click any key your keyboard doesn't have to take it out of the count. Extra keys such as F13–F24, media keys, macro keys and knobs show up under Extra keys.

US-ANSI, UK-ISO, DE-ISO, FR-ISO, ES-ISO, IT-ISO, JP-JIS and KR-ANSI. Each one shows the same legends as the keycaps, such as QWERTZ for German and AZERTY for French. On Auto, the tester starts from your computer's keyboard setting and switches when it detects an ISO, JIS or Korean key.

ANSI keyboards have a wide, single-row Enter key and a long left Shift. ISO keyboards have a tall, two-row Enter key and an extra key next to a shorter left Shift. JIS (Japanese) keyboards add keys around the space bar and next to Backspace and right Shift. Korean (KR-ANSI) keyboards use the ANSI shape with Hangul legends, and right Alt and right Ctrl work as 한/영 and 한자.

Yes. Choose FR-ISO for AZERTY or DE-ISO for QWERTZ and the keys show the same legends as yours. The tester reads the physical position of each key, so the correct key lights up whatever language your computer is set to.

Yes. Cmd and Option light up in the Win and Alt positions. Caps Lock on a Mac may need two presses to register. Mac keyboards don't have Insert or a Menu key, so click those to mark them as not on your keyboard.

Yes, as long as a physical keyboard is connected by USB or Bluetooth. The on-screen touch keyboard doesn't send the same signals, so it can't be tested here.

Check the cable or wireless connection first and try another USB port. Wireless keyboards may also need charging or re-pairing. Some gaming keyboards have a Win lock or game mode that turns off certain keys on purpose. If a key still stays grey, the switch or its solder joint may have failed.

Fn is handled inside the keyboard itself and never sends a signal to your computer, so no website can detect it. Test it by using it: if Fn plus a media key changes your volume, it works.

Your operating system may keep these keys for itself, or your keyboard's Win lock may be on. That's why they're optional and don't count against your result.

This is called key chatter, and it's usually caused by a worn or dirty switch. If a key fires again within 30 ms of being released, the tester marks it in yellow as possible double typing. Try cleaning the key with compressed air. On hot-swappable keyboards you can replace the switch in seconds, and some keyboard software also lets you raise the debounce time.

Check that your system language layout matches your keyboard, and that no remapping software or keyboard macro is changing the key. On many European layouts, right Alt works as AltGr; the tester filters out the extra Ctrl signal Windows sends with it.

While the tester is on screen, it catches keys like Space, the arrows, Tab and F5 so they don't scroll or reload the page. Scroll with your mouse, or click Pause. A few browser shortcuts, such as Ctrl+W and Alt+F4, can't be blocked by any website, so avoid them while testing.

It shows how many keys your keyboard can report at the same time. This is called key rollover. Many standard keyboards stop at 6 keys (6KRO), while N-key rollover (NKRO) keyboards can report every key together. Some keyboards only use NKRO in wired mode or reduce rollover over Bluetooth, and your operating system or browser may cap the number too.

Probably not. That's ghosting: on keyboards without full anti-ghosting, certain combinations block each other. It's a limit of the design, not a fault. For gaming, check that the combinations you actually use all register.

No. This tool checks whether each key registers, how many work together, and whether any key is double typing. Latency and polling rate need dedicated tools.