Keyboard Tester
Test your keyboard online: every key lights up as you press it, so dead, stuck or double-typing keys stand out. Shows key codes, held keys and rollover. Works for laptop and external keyboards.
How it works
- 1
Click the page
Click anywhere on the page so it receives your key presses.
- 2
Press every key
Keys light up while held and turn green once they've worked.
- 3
Look for problem keys
Keys that never turn green, or show a chatter warning, need attention.
- 4
Test combinations
Hold several keys at once to see how many your keyboard can register together.
Common uses
- Check a second-hand or refurbished laptop keyboard before buying it.
- Find out whether a key that doesn't type is a hardware fault or a layout setting.
- Test how many keys a gaming keyboard registers at once.
About the Keyboard Tester
Test your keyboard online: every key lights up as you press it, so dead, stuck or double-typing keys stand out. Shows key codes, held keys and rollover. Works for laptop and external keyboards.
Each press is identified by its physical position (the browser's KeyboardEvent.code) rather than the character it types, so the tester works with any language layout. Chatter detection watches for a second press arriving within 35 ms of the key being released — faster than anyone presses a key twice on purpose.
Keyboard Tester is part of a free, privacy-first toolkit. It uses your browser's built-in device APIs, so it starts instantly with nothing to install — and nothing you type, say or show ever leaves your device.
Because keyboard tester works without any sign-up or installation, you can use it as often as you like and it's always available — on desktop or mobile, and even offline.
Explore more device tests, or try Mouse Test · Dead Pixel Test.
Related tools
Related guides
Keyboard Tester — FAQ
Open the tester and press every key. Each key lights up while held and stays green once it has worked, so any key that never turns green isn't registering.