Keyboard Tester
Press every key on a live on-screen keyboard - tested keys turn green, stuck keys and rollover limits are flagged
100% free. Runs entirely in your browser - your files and data never leave your device and nothing is uploaded to any server.
A physical keyboard is needed. On a phone or tablet, connect a Bluetooth or USB keyboard first.
Not tested Tested Held now Possibly stuck Click a key on screen to see what it should send.
Modifier keys
Left and right are separate keys - test both. Some laptops have no right Win/Menu key.
N-key rollover / ghosting
Hold as many keys as you can. If a key you are holding does not light up, the keyboard has reached its rollover limit (cheaper boards often stop at 2-6 keys, especially with letters near each other).
Key details
Click any key on the on-screen keyboard to see the code your browser should receive for it, its position and its test status.
Event log - last 50
Every keydown, keyup and auto-repeat appears here with its time, so you can spot a key that fires twice or releases late.
Fn and media keys (volume, brightness, play) are handled by the keyboard or the operating system and usually never reach the browser, so they cannot be tested here. Print Screen often only sends a key-up, and some system shortcuts (Win key, Alt+Tab, Ctrl+W) are taken by the OS before any web page sees them.
About this tool
A live on-screen keyboard that lights up as you press each key, so you can see at a glance which keys work and which you have not reached yet. Tested keys turn green and a progress bar counts down the keys left until the whole board is done. It flags a key held down for more than two seconds as possibly stuck, measures N-key rollover by counting how many keys register at once, and shows left and right modifiers separately. Switch between QWERTY (US and UK), QWERTZ, AZERTY and Mac layouts, and between full-size, TKL and 60% boards. When you finish, copy or download a report listing any keys that never registered - useful for a warranty claim, a seller or your IT team. Everything runs in your browser; nothing you type is sent anywhere.
How to use this tool
- Pick your layout and sizeChoose QWERTY, QWERTZ, AZERTY, UK or Mac, and full-size, TKL or 60%, so the on-screen board matches yours.
- Press every key onceEach key turns green when it registers. The progress bar shows how many are left.
- Check modifiers and rolloverTest left and right Shift, Ctrl, Alt and Win/Cmd separately, then hold several keys together to see your rollover limit.
- Watch for stuck or repeating keysA key held for over two seconds is flagged as possibly stuck, and auto-repeats are counted on the key itself.
- Copy or download the reportThe report lists untested keys, stuck keys and your rollover result - ready to send to a seller or IT.
Checking a keyboard before buying or after a spill
Press every key and watch it turn green - any key that stays grey did not register. Hold several keys together to check rollover, which matters for gaming; a key flagged as stuck may have debris under it.
Fn, volume and brightness keys are often handled by the keyboard or the operating system itself and never reach the browser, so they may not light up even when they work.
Key features
- Full visual keyboard - every key lights up as you press it.
- Progress bar and an "All keys tested" badge, so no key is skipped.
- Stuck-key warning, auto-repeat counter and repeat rate per key.
- N-key rollover / ghosting test for gaming and mechanical keyboards.
- QWERTY, QWERTZ, AZERTY, UK and Mac layouts; full, TKL and 60% sizes.
- Event log with millisecond timing, plus a copyable and downloadable report.
Common uses
- Checking a used keyboard or laptop before you buy it.
- Confirming a key is really dead before a warranty or RMA claim.
- Testing a new mechanical keyboard for ghosting and rollover.
- Verifying a laptop keyboard after a spill or repair.
Tips for better results
- Test left and right modifier keys separately - they are different keys.
- Use Focus mode to go fullscreen so Space and arrows never scroll the page.
- Switch to "F-keys only" or "Numpad only" to finish one area at a time.
- Click any key on the on-screen board to see the code it should send.
Mistakes to avoid
- Expecting Fn or media keys to register - they are handled by the keyboard or OS, not the browser.
- Treating an OS shortcut (Win key, Alt+Tab, Ctrl+W) as a dead key - the system takes it first.
- Testing rollover with keys right next to each other only; try spread-out keys too.
- Forgetting to set the layout, then wondering why legends do not match the keycaps.
Frequently asked questions
Press it. If the matching key on the on-screen keyboard turns green, the key works. If nothing lights up after a few firm presses, the key is not reaching the computer - try another USB port or computer to rule out the connection before blaming the switch.
Yes. Any key held down for more than two seconds turns orange with a warning. If you are not touching it, the key is stuck - often from debris or a sticky spill.
Rollover is how many keys a keyboard can register at the same time. Hold as many keys as you can: the "most at once" counter shows how many registered. If a key you are holding does not light up, you have reached the limit (ghosting). Many office keyboards stop at 2-6 keys; gaming keyboards often handle far more.
Those keys are handled inside the keyboard or by the operating system and are never sent to a web page, so no browser-based tester can see them. That is normal, not a fault.
US QWERTY, UK QWERTY, German QWERTZ, French AZERTY and Mac, in full-size, TKL (no numpad) and 60% sizes. Keys are matched by their physical position, so they light up in the right place whatever language your computer types in.
Yes. Copy the report or download it as a text file. It lists untested keys, keys held long enough to look stuck, auto-repeats and your rollover result.
No. The test runs entirely in your browser and nothing you press is uploaded or stored.
Only with a physical keyboard connected over Bluetooth or USB. On-screen phone keyboards do not send the same key events.