This keyboard tester shows, key by key, what your computer receives. Click Start test and press every key once: each key that registers gets a check mark, and the counter shows how many are left. It also shows the key code, measures how many keys register at once, flags double typing and builds a report. It is one of the free ghacks tools.
How to test your keyboard
Click Start test and press every key once; tested keys turn green and Keys tested shows how many are left.
- Pick your Layout (such as US QWERTY (ANSI) or UK QWERTY (ISO)), the Size and the Modifier keys (Windows or macOS).
- Click Start test and press every key once. Tab, arrows, Space and F keys are captured inside the test area.
- Choose a Combo under Rollover and ghosting test, click Run, hold the keys together and release them.
- Check Chatter suspects for keys that double-typed.
- Click Copy report. To leave, hold Esc for 1 second, click Stop test or click outside the test area.
What the colors, badges and counters mean
Green with a check mark means the key registered at least once, a filled key is held right now, and a red badge marks a possible chatter or stuck key.
| You see | Meaning |
|---|---|
| Green key with a check mark | Registered at least once |
| Filled key | Held down now |
| Red border, badge such as !2 | Chatter suspect, with the number of suspect presses |
| Badge 5s+ | Held for more than 5 seconds: stuck key? |
How to test for keyboard ghosting and n-key rollover
Hold several keys at once: if a held key does not light up, the keyboard is blocking it; if a key you did not press lights up, that is ghosting. The guided combos, such as WASD with Shift and Space, name every missing key as blocked and every extra key as phantom.
What is n-key rollover?
N-key rollover (NKRO) is the number of keys a keyboard registers correctly when they are held at the same time. 2KRO means two keys, 6KRO means six regular keys plus the modifiers, the limit of the standard USB boot keyboard report, and NKRO means every key. Most keys at once reports your result: exactly 6 may be that boot limit, which some keyboards switch to in BIOS mode or behind a KVM switch, and 10 or more means NKRO is likely, not proven.
What is anti-ghosting?
Anti-ghosting is a design that stops phantom keys, with a diode per switch or with logic that blocks keys it cannot read reliably. An anti-ghosting keyboard can still block keys, so it is not the same as NKRO.
How to detect key chatter (double typing)
Chatter is a worn or dirty switch sending two presses for one; the tester flags a key when its next press follows the release within 50 ms. Set the Chatter threshold from 20 to 100 ms; autorepeat never counts. Windows Filter Keys (bounce keys) can hide chatter, so switch it off first. For fixes, see how to diagnose keyboard chatter with Switch Hitter.
event.code vs event.key: why both are shown
event.code names the physical key position and stays the same on every layout; event.key is the character that position produces with your current layout.
| event.code | event.key on US | event.key on German |
|---|---|---|
KeyZ |
z | y |
KeyY |
y | z |
Semicolon |
; | ö |
IntlBackslash |
(no such key on ANSI) | < |
AltRight |
Alt | AltGraph (Windows also sends ControlLeft) |
Equal |
= | Dead |
The Last key panel shows key, code, location, repeat and hold time; the Event log lists the last 50 events. To change what a key does, see our guide to keyboard remapping.
ANSI vs ISO: which layout does your keyboard have?
ISO keyboards have an extra key next to the left Shift and a tall, L-shaped Enter; ANSI keyboards have a wide left Shift and a one-row Enter. Press that extra key and the tester switches to the ISO view; in Chrome, Edge and Opera it also detects a QWERTZ system layout. A full-size Windows board has 104 keys on ANSI and 105 on ISO.
Keys and tests a browser cannot see
A web page only receives what the operating system passes on, so some keys are out of reach.
| Key or test | Why |
|---|---|
| Fn | Handled in the keyboard firmware, never sent |
| Ctrl+Alt+Del | Taken by the operating system first |
| Windows key, Alt+Tab, Esc | Only with Full-screen capture in Chrome, Edge or Opera |
| Print Screen (Windows) | Only the release reaches the page |
| Media and vendor keys | Listed under Other keys if the system passes them on |
| Polling rate, latency | Not measurable in a browser |
If your volume keys never show up, see how to fix USB keyboard volume keys on Windows 11.
Can you test keyboard latency or polling rate online?
No, no browser tool can measure true polling rate or input latency, because the browser sees one event per key change and the operating system adds its own delay. The tester shows hold time and event gaps instead; real latency needs a USB analyzer or a high-speed camera.
A key failed the test: what next?
If a key never lights up on two different computers, the keyboard is at fault; if it works elsewhere, the problem is software.
- Dead on both: attach the copied report to your warranty or RMA claim.
- Works elsewhere: check layout and driver settings.
FAQ
Is an online keyboard tester safe?
This one is. It runs in your browser, keystrokes are never stored or sent, and the log disappears when you leave the page. Keys are only captured while the test area has focus. Once loaded, it works offline, so you can disconnect and keep testing. Do not type passwords into any tester anyway; pressing each key once is enough.
Does it work on a Mac or Chromebook keyboard?
Yes for a Mac: set Modifier keys to macOS and the drawn keyboard shows cmd and opt in place of Win and Alt. A Chromebook keyboard works too, because ChromeOS runs Chrome, but there is no ChromeOS view yet, so some keys carry Windows labels on the drawing.
Why does my Fn key not light up?
The Fn key never leaves the keyboard. Its firmware uses Fn to change what other keys send, for example turning F1 into a media key, so the browser never sees Fn itself. Test it indirectly: hold Fn, press a function key and check whether a media key appears under Other keys.
Why do two keys light up when I press AltGr?
On Windows, AltGr on a German or other European layout is sent as Left Ctrl plus Right Alt. The tester recognises that pair, shows a note and counts it as one AltGr press, so it is not ghosting. Pick an ISO layout to see the key labelled AltGr.
Test the rest of your setup with the microphone test and the webcam test. For typing speed, try these typing games and tests.