Keyboard Test

What the Keyboard Test checks

The test checks one thing: whether your browser receives a key press and a key release when you use each key. The on-screen keyboard is a simplified ANSI-style layout of 73 keys: Esc, F1–F12, the number row, the three letter rows, Shift, Ctrl, Win, Alt and Space. A key is highlighted while you hold it down and turns green once you have pressed it at least once, so a quick pass over the whole keyboard shows at a glance which keys never registered.

The drawing has no numeric keypad, arrow cluster or navigation block. Keys outside it still appear in the “last events” list by their code, but they don't light anything up.

How it works

Every key is identified by KeyboardEvent.code, which names the physical position of the key rather than the character it types. That is why the same key lights up on QWERTY, AZERTY and Spanish layouts, and why the highlighted key can differ from the letter printed on your keycap.

While the page is open it blocks the browser's default action for Space, Tab and F1–F12, so you can test them without the page scrolling, changing focus or reloading. The side effect is that you can't Tab between controls or press F5 here; use the mouse to leave.

If you hold a key, the operating system repeats it. The browser flags those repeats and the page shows a warning naming the key, because a repeat is normal while you hold the key and suspicious when you only tapped it.

Reading what you see

Testing one suspect key

A single pass over the keyboard finds keys that never register. A key that types twice, or only sometimes, needs a slower look:

1. 01

   Press Clear results first

   It empties the “last events” list and the repeat warning. The warning otherwise stays on screen until you clear it, so an old one can be mistaken for a new one.

2. 02

   Tap the key slowly, ten times

   The list puts the newest code first and keeps the last twelve entries. Ten separate taps should leave ten entries of the same code; more than ten means the browser received extra presses.

3. 03

   Hold it for a second, then let go

   While the key is held, the operating system repeats it: the list fills with the same code and the warning names the key. That's normal. What to watch is the highlight going out when you let go.

4. 04

   Repeat it somewhere else

   Try another USB port or cable, or another computer, before deciding the key itself is at fault.

What this test can't tell you

It can't tell whether a key that registers feels damaged, sticky or inconsistent, and it doesn't detect ghosting by itself: when you hold several keys you see which ones the browser received, and the judgment is yours. It says nothing about key latency or actuation force. Function-layer keys, media keys and Fn combinations are often handled inside the keyboard and never reach the computer, and the operating system can intercept some shortcuts before the page sees them, so a key that stays dark is not always a broken key. The guide on what browser tests can and can't measure covers these limits for every tool on the site.

What to do next

If a key fails on more than one computer, the keyboard is the likely cause; if it fails only on this one, look at drivers, remapping software or the connection, and the keyboard guide goes through those causes in order, including the Windows and macOS accessibility settings that can make keys ignore or repeat presses. Once every key registers, the Typing Speed Test checks how the keyboard behaves in a real typing run, and the Mouse Test does the same job for your pointing device.