How to test your keyboard
- Pick your layout: US (ANSI), UK and Europe (ISO) or Mac. Click the board, then press any key. It lights up while you hold it and turns green once it has worked.
- Work through every key, including the function row, arrows and number pad. The line above the board shows the last key, its code and keyCode, plus how many keys you’ve tested.
- Press Reset to clear the board and start again, for example after cleaning the keyboard.
Reading the key info
Each press fills in three values above the board. They describe the same key in different ways, which helps when you set up shortcuts or debug a program.
| Value | What it means | Example |
|---|---|---|
| Key | The character or name the key produces with your current layout | a, A, Enter |
| Code | The physical position of the key, the same on any layout | KeyA, ShiftLeft |
| keyCode | An older number for the key that some software still uses | 65 |
The Key value changes with Shift and your layout, so the same key can show a or A. Code never changes for a given key, which is why the board uses it to light up the right spot.
Testing for ghosting (key rollover)
Many keyboards wire their keys in a grid, and some combinations of three or more keys can’t be told apart on that grid. When that happens the keyboard ignores one of the keys. This matters most in games, where you might hold W, A, Shift and Space at the same time.
To test, hold the keys you use together and look at the board. All of them should be lit while you hold them. If one stays dark, try the same keys in a different order. A key that only fails in a certain combination points to a rollover limit, not a broken key.
When a key doesn’t register
- Try it a few times. A key that works only now and then often has dirt or crumbs under it. Turn the keyboard over and shake it, or use compressed air.
- Change the port or connection. Plug a wired keyboard into another USB port, or replace the batteries in a wireless one.
- Try another computer. If the key fails there too, the keyboard itself is at fault. If it works, look at drivers or keyboard software on your computer.