What is it?
The Keyboard Tester shows which keys work: every key you press lights up on a full keyboard map, with its key code, and it tests how many keys register at the same time (rollover).
Who is it for?
People who just bought, cleaned or spilled tea on a laptop or keyboard, buyers of second-hand laptops, and gamers checking key rollover.
How to use it
- “Click or tap the keyboard below, then press keys”
- Press every key; tested keys stay lit.
- Hold several keys at once to test rollover; Reset to start again.
After a spill
Switch the laptop off immediately, turn it upside down to drain, and let it dry for 24–48 hours before testing. Sticky keys may need cleaning by a technician.
Errors and how to fix them
- A key doesn’t light: it may be faulty, or blocked by the system (Windows key, Fn keys, media keys may not reach the page).
- Keys work in other apps but not here: click the page first so it has focus.
- Wrong key lights: your keyboard layout setting doesn’t match the keyboard.
Questions people ask
- Does it work for laptop keyboards? Yes, and external USB or Bluetooth keyboards.
- What is rollover? How many keys register at once; gaming keyboards handle more.
Practical tip
Test second-hand laptops before paying: press every key, including Fn combinations for volume and brightness, and hold Shift with several letters to check rollover.
Open the tool: Keyboard Tester
Still stuck?
Contact support. Tell us which tool or page you were using, what you tapped, what you saw, and your phone or computer and browser (for example: Android phone, Chrome). We reply by email.
Questions, or an error not listed here?
Tell us in the comments: what you were doing, the exact message you saw, and your device and browser. We read every comment and add new fixes to this article.