Find the cause step by step
- Press the key in the box above. Does it show up? Note it.
- It doesn’t: shut down the laptop, tilt it and blow compressed air between the keys. After a spill, shut it down right away and let it dry for at least 48 hours before turning it on.
- Several neighboring keys dead at once usually means a loose keyboard cable or spill damage: take it to a repair shop and use a USB keyboard meanwhile.
- Shows up here but doesn’t type right: check the layout (US or UK), Num Lock and Filter Keys.
Symptom, cause and fix
| Symptom | Likely cause | What to do |
|---|---|---|
| Key doesn’t show up in the test | Dirt or a damaged membrane | Clean; replace the key or the keyboard |
| Several neighboring keys dead | Loose keyboard cable or a spill | Repair shop; USB keyboard meanwhile |
| @, " or # in the wrong place | UK layout on a US keyboard (or the reverse) | Switch the layout to match your keys |
| Letters typing numbers | Num Lock on | Turn off Num Lock (on many laptops, Fn + NumLk) |
| You have to hold the key down | Filter Keys on | Turn it off under Accessibility › Keyboard |
Where to find it on your device
- Layout on Windows 11: Settings › Time & language › Language & region › your language › ⋯ › Language options › Keyboards.
- Filter Keys: Settings › Accessibility › Keyboard › Filter keys: Off.
Related questions
How do I know if the problem is the keyboard or Windows?
If the key doesn’t show up in the browser test, the signal isn’t reaching the system: the problem is physical. If it shows up here but doesn’t work in an app, it’s a setting or the app itself.
The Fn key doesn’t show up in the test. Is it broken?
No. Fn is handled inside the keyboard and no website can detect it. Try a combination, like Fn plus a volume key, and see if it does its job.
Can I replace just one laptop key?
Sometimes: the keycap and its plastic hinge can be bought separately for some models. If the membrane underneath is damaged, the whole keyboard has to be replaced.
The J, K, L and ; keys stopped together. What is it?
Neighboring keys that stop at the same time usually share a trace on the keyboard: a spill, dirt underneath or a loose cable. List every failing key with the test above and take the list to a repair shop; a USB keyboard works meanwhile.
A key is not working on my Dell, HP or Lenovo laptop. Does the brand change anything?
The steps are the same on every brand: test here, clean, check the layout and Num Lock. What changes is the setup key to test in the BIOS (F2 on Dell, F10 on HP, F1 or F2 on Lenovo) and the maker’s app for drivers.
More problems: keyboard test
- Laptop keyboard not working: what to do first
- Keyboard typing by itself: how to fix it
- Keyboard typing numbers instead of letters: how to fix it
- Keyboard typing wrong characters: @ and " swapped, # turned into £
- Keyboard typing double letters: how to fix it
- Keyboard locked: how to unlock it
- Mechanical keyboard key not working: how to fix it
- USB keyboard not working on your PC: how to fix it
- How to test a keyboard without a computer: use your phone
- How to test a keyboard: online, mechanical, wireless, MacBook and BIOS
Updated November 12, 2026.