How to use the keyboard tester
- Click anywhere on this page so it has focus.
- Press each key on your keyboard one at a time.
- Keys light up while held down and turn green once tested. Any key that stays grey after you press it did not register.
- The panel shows the key value, physical code and location for every press, which is useful when remapping keys.
Common problems this finds
Dead keys
A key that never turns green is not sending a signal. On mechanical keyboards this is often a bad switch or solder joint. On laptops it can be debris under the keycap or a failing ribbon cable.
Sticky or repeating keys
If a key stays highlighted after you let go, it may be physically sticking. Compressed air under the keycap often fixes this.
Ghosting
Hold several keys at once, like W, A and Shift. If some do not light up, your keyboard has limited rollover. Many office keyboards can only register a few keys at the same time, while most gaming keyboards handle many.
Keys that are hard to test in a browser
Some keys are reserved by your operating system and may never reach a web page, such as the Windows key on some systems, Fn, and media keys. Print Screen often only registers on release. This does not mean those keys are broken.
Frequently asked questions
Does this work with non QWERTY layouts?
Yes. The tester reads the physical position of each key, so AZERTY, QWERTZ and other layouts work.
Why does the Fn key not light up?
On most keyboards Fn is handled by the keyboard itself and is never sent to the computer, so no website can detect it.
Can I test a laptop keyboard?
Yes. The diagram includes a full size layout, so a laptop without a number pad will simply leave those keys untested.
Is anything I type recorded?
No. Key presses are only used to light up the diagram and are never saved or sent anywhere.
How do I test key rollover?
Hold down several keys at the same time and see how many light up together.