Keyboard Tester
Test every key on your keyboard and read its key code, location and rollover.
Find The Key That Is Not Working
A key that sometimes fails is maddening, and hard to prove. Click into the test area and press each key in turn: it lights while held and stays marked once it has worked, so the one that never lights is the one to worry about. Press several together to test rollover — how many simultaneous keys the keyboard reports before it starts dropping them, which matters for gaming and fast typing.
Each press also shows the values a web page receives — event.key, event.code, the legacy keyCode and the key’s location — which is exactly what a developer needs when handling keyboard shortcuts. While the test area has focus it stops keys from scrolling or navigating the page; press Escape twice to leave.
Key features
- Full keyboard map — main block, function row, navigation cluster and arrows.
- Tested keys stay marked — so a dead key stands out.
- Rollover test — the most keys held at once, for ghosting checks.
- Developer details — event.key, event.code, keyCode, location and modifiers.
- Extra keys listed — numpad and media keys that are not on the drawing.
This tool runs entirely inside your browser using native Web APIs. Your files and text are never uploaded to a server, never logged and never shared with third parties.
How to use: Keyboard Tester
- Click the test area
It captures keys until you press Escape twice. - Press every key
Each lights when held and stays marked once it works. - Test combinations
Hold several keys together and watch the rollover count. - Check the details
Key values and codes for the last key appear below.
Technical specifications
| Processing location | Entirely in your browser — no server round trip |
|---|---|
| Data uploaded | None. Files and text never leave your device |
| Price | Free — no account, no trial, no usage cap |
| Category | Developer |
| Works offline | Yes, once the page has loaded |
| Browser support | Chrome 90+, Edge 90+, Firefox 90+, Safari 15+ |
| Interface languages | English, 中文, हिन्दी, Español, العربية |
Frequently asked questions
What is key rollover?
How many keys a keyboard can register at the same time. Many office keyboards manage two or three plus modifiers; gaming keyboards often advertise n-key rollover, meaning every key. When a combination exceeds the limit, some keys are dropped — that is ghosting.
What is the difference between event.key and event.code?
event.key is the character or action the key produces with the current layout and modifiers, such as "a", "A" or "Enter". event.code is the physical key position, such as "KeyA", which stays the same whatever the layout. Use code for games and position-based shortcuts, key for text.
Why does the Windows key or Print Screen not show?
The operating system handles some keys itself before the browser sees them, and some keyboards send no key-release event for Print Screen. That is normal and not a fault in the keyboard.
Why do my Fn keys not register?
On most laptops the Fn key is handled inside the keyboard itself and never sent to the computer; it changes what the other keys send instead.
Can I test a phone keyboard?
Not usefully. On-screen keyboards report text rather than physical keys, so key codes and rollover do not apply. This test is for physical keyboards.