How to use the keyboard tester
- Choose your Layout: US (ANSI), UK (ISO), Brazil (ABNT2), Latin America (ISO) or Spain (ISO).
- Turn Numeric keypad off if your keyboard has no number pad (laptops and compact boards).
- Press every key once. The counter shows how many of the keys on the drawing you have tested.
- Hold several keys together to see the most keys registered at once.
- Press Reset to start over, for example after cleaning or swapping a switch.
The tester reads the physical position of each key, so it lights the right spot even when your system is set to a different language. Last keys lists the characters your system typed, most recent first (keys without a character show their name).
What the result means
- A key that stays grey after you press it is not reaching the computer. Try it again firmly; if it still fails, it is a hardware fault (dirt, a worn switch or a broken trace).
- A key that lights up but types the wrong character in your documents is fine: the keyboard layout set in the system is wrong (see below).
- One press that lights up twice in Last keys points to chatter, a common fault of worn mechanical switches.
- Fn and some system keys (Windows key, Print Screen) are handled by the system and may not show up. That is normal, not a fault.
Ghosting and rollover
Most keys at once shows the largest number of keys the keyboard reported together. Many office keyboards with rubber membranes manage only 2 or 3 keys in some combinations; gaming keyboards are often 6-key or N-key rollover. If a key stops lighting up while you hold others, that combination is beyond what the keyboard can report, which is called ghosting or blocking. Test the combinations you really use in games, like W, A, Shift and Space together.
On a Mac, holding Command can stop the browser from seeing other keys being released. Test rollover without Command, or count only the keys that light up.
Wrong characters: the layout is set wrong
If the tester lights the correct key but your text shows a different symbol, the keyboard is working and the system expects another layout. Typical signs: on a UK keyboard set to US, Shift+2 types @ where the keycap shows a quotation mark; on a Brazilian ABNT2 keyboard set to US, the Ç key types a semicolon; on a Latin American keyboard set to Spain, symbols like @ and the brackets move.
- Windows 11: Settings > Time & language > Language & region. Click the three dots next to your language, choose Language options, then Add a keyboard and pick the layout printed on your keys. Remove the wrong one in the same place.
- Windows shortcut: Windows key + Space switches between installed layouts, which is often how the wrong one gets turned on by accident.
- Mac: System Settings > Keyboard > Text Input > Edit, then add the input source for your keyboard with the + button.
- iPhone and iPad with an external keyboard: Settings > General > Keyboard > Hardware Keyboard. On Android, look for the physical keyboard section of the keyboard settings (the name varies by brand).
A key does not work at all
- Unplug and reconnect the keyboard, or try another USB port. For wireless keyboards, replace or charge the battery and pair it again.
- Clean under the key with compressed air. On mechanical keyboards, a single dead key is often one switch that can be replaced.
- Try the keyboard on another computer. If the same key fails there too, it is the keyboard; if it works, look at the drivers or the remapping software on the first computer.
Questions
How do I test if all my keyboard keys work?
Pick your layout, then press every key once. Keys turn green when they work; any key left grey after a firm press is the one to check.
Why doesn't the Fn key show up?
On most keyboards Fn is handled inside the keyboard itself and never sends a key to the computer, so no browser can see it. Test it by using Fn combinations instead, such as volume or brightness.
How do I check keyboard ghosting?
Hold the keys you press together in games and watch Most keys at once. If one of them does not light up, that combination ghosts on your keyboard.
Can I test a laptop keyboard?
Yes. Turn Numeric keypad off if the laptop has no number pad, then press every key. Nothing is installed and the test also works offline.