This keyboard tester helps you verify that every key on your keyboard is working correctly.
It's especially useful when buying a used keyboard or testing a new mechanical keyboard.
Testing Process:
- Click anywhere on this page to focus the keyboard input
- Press each key on your physical keyboard
- Watch the virtual keyboard - keys turn green when pressed
- Previously pressed keys turn blue
- Keys held for 3+ seconds turn red (potential stuck key)
- Test modifier keys (Shift, Ctrl, Alt) with other keys
What to Check:
✓ Good Signs:
- All keys register when pressed
- Keys return to normal when released
- No double registrations
- Consistent key feel across keyboard
✗ Problems to Find:
- Keys that don't register
- Keys that register multiple times
- Keys that stay "pressed" (stuck)
- Inconsistent registration
Common Keyboard Issues:
Dead Keys
Keys that don't register at all. Common causes:
- Damaged switch (mechanical keyboards)
- Worn membrane (membrane keyboards)
- Debris under the key
- Circuit board damage
Chattering Keys
Keys that register multiple times with one press. Solutions:
- Clean the switch with compressed air
- Replace the switch (hot-swappable keyboards)
- Adjust debounce time in software
- Use contact cleaner for older keyboards
Stuck Keys
Keys that stay registered after release. Try:
- Remove keycap and clean underneath
- Check for sticky substances
- Ensure keycap is properly seated
- Test without the keycap installed