Press any key to begin…
Fn and some media keys are handled inside the keyboard hardware and can never appear in any software test.
Quick answer: Click anywhere on the keyboard graphic below (or just start typing). Every key you press lights up blue while held and stays green once tested – so a key that never turns green is faulty. The counter shows how many keys register at once (rollover).
Buying a used laptop or mechanical keyboard? Coffee spill? This tester lights up each key as your keyboard reports it, making dead keys, double-typing (chatter) and stuck keys obvious in under a minute. It reads the same key events every app receives, so if a key registers here, the hardware is fine and any problem lies in software.
It also measures key rollover – how many keys your keyboard can register simultaneously. Budget keyboards often handle only 3–6 keys at once (you'll see “ghosting” where extra presses vanish), while gaming keyboards offer N-key rollover. Hold down as many keys as you can and watch the max counter.
How to test your keyboard online
- Click once inside the tool, then press any key – it flashes blue while held and stays green after release.
- Work across every row, including modifiers (Shift, Ctrl, Alt), F-keys and arrows.
- Watch for keys that type twice per press (chatter) in the key history line.
- For rollover, press and hold multiple keys together – the “max at once” counter records your keyboard's limit.
- A key that never turns green here is dead at the hardware/driver level.
Why use the GadgetsFocus keyboard tester?
- Full visual layout – tested keys stay green so you can see what's left.
- Shows each key's exact name and code (useful for remapping and gaming configs).
- Rollover counter reveals how many simultaneous presses your keyboard supports.
- Key history exposes chatter (one press typing two characters).
- Works with laptop, USB, wireless and Bluetooth keyboards – nothing to install.
Honest limitations
- Some keys never reach the browser: Fn (handled inside the keyboard itself), the Windows/Power/Eject specials on certain laptops, and media keys on some models – those not lighting up is normal, not a fault.
- Browser-reserved shortcuts (like Ctrl+W or F11) may trigger their action; we suppress what we safely can, but a few combos belong to the browser or OS.
- The layout drawn below is standard US ANSI – if your physical layout differs (ISO Enter, AZERTY), keys still register and turn green, just in slightly different positions.
- Rollover results can be limited by USB mode or the OS, not only the keyboard.
Frequently asked questions
A key lights up here but doesn't work in my program – why?
Then the hardware is fine. Check the app's own keybindings, language/input settings, or software like AutoHotkey and gaming utilities that remap keys system-wide.
What does the rollover number mean?
It's the maximum keys registered simultaneously. 6-key rollover (6KRO) is typical for office keyboards and fine for typing; gamers pressing many keys at once benefit from NKRO (unlimited). Test it by mashing keys in one area of the board.
Why doesn't my Fn key light up?
Fn is processed inside the keyboard's own controller and is never sent to the computer, so no software on earth can see it directly. Test it indirectly: press Fn plus a function key and see whether the combined action fires.
How do I spot key chatter?
Press a key once, cleanly. If the history line shows the same key twice for one press, the switch is chattering – common on worn mechanical switches. Compressed air sometimes helps; otherwise the switch needs replacing.
Does this work for Bluetooth and wireless keyboards?
Yes – the browser sees them exactly like wired ones. If a wireless keyboard fails here, first swap batteries or re-pair before blaming the keys.
Related tools: Typing speed test · CPS click test · Gamepad tester · Reaction time test
Last updated: July 11, 2026. Built and tested by the GadgetsFocus team on Chrome, Edge, Firefox and Safari (desktop & mobile). Everything on this page runs locally in your browser — we never see, store or transmit your files.