Keyboard Test — Check Every Key Online
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About the Keyboard Test
A keyboard test tells you something a word processor cannot: whether every key on your keyboard actually reaches the computer. When a key stops working, the cause is usually one of three things — dirt or damage under the keycap, a driver or layout problem in the operating system, or a cable and connector fault. This test rules out the software layer first, because it reads keys exactly as the browser receives them.
Press a key and the matching key on the diagram lights up. Keys you have already pressed stay marked, so you can work across the board and see at a glance which ones never responded. The readout underneath shows the physical key position, the character it produced, and the legacy key code, which is useful when a key registers but produces the wrong character.
The test runs entirely in your browser. Nothing you type is sent anywhere, stored, or logged.
How to test your keyboard
- Click anywhere on the keyboard diagram to give it focus. The hint above turns green when it is listening.
- Press keys one at a time and watch them light up. Each key you press stays marked so you can track your progress.
- Work through the whole board, including the modifiers, arrows and function row.
- Check the counter. If it stops short of the total, the keys still unmarked are the ones that never reached the browser.
- Press Reset to clear the marks and run through the board again.
Frequently asked questions
A key lights up here but does not work in my other programs. Why?
If the key registers in this test, the hardware and the connection are fine. The problem is above that layer — usually a keyboard shortcut claimed by an application, a stuck modifier key, or a remapping tool running in the background.
A key does not light up at all. Is my keyboard broken?
Not necessarily — and one case is not a fault at all. A key that exists only on your layout has no square on the US diagram, so it stays dark while working perfectly; press it and its name appears in the Code line below the keyboard, which is the proof it reached the browser. For every other key, try it in a different port or on another computer. If it fails there too, the switch under the keycap is the likely cause. On membrane keyboards, a single dead key often means debris or liquid under the sheet.
Why do some function keys do nothing?
On many laptops the top row is handled by the firmware for brightness, volume and similar controls. Those presses never reach the browser at all. Holding the Fn key, or switching the function-key behavior in your BIOS settings, usually makes them send normal F-key signals.
My keyboard is not a US layout. Will the diagram still be right?
Keys that a US keyboard also has will light in the right place, because the test reads each key by its physical position rather than by the character printed on it — a QWERTZ or AZERTY board highlights the correct square despite the US labels. Keys that exist only on your layout are the exception: the extra key beside the left Shift on ISO boards, and the five Japanese-layout keys your browser calls Convert, NonConvert, KanaMode, IntlYen and IntlRo, have no square on this US diagram, so pressing them lights nothing. They are not broken. Press one and its name appears in the Code line under the keyboard — that readout is proof the key reached the browser.
Can I test whether my keyboard handles many keys at once?
Yes. Hold several keys down together and see how many light up at the same time. Cheaper keyboards typically stop registering after two or three simultaneous keys in the same area, which matters for gaming. On spec sheets this is the figure sold as anti-ghosting or N-key rollover. Two different ceilings hide behind that one figure, and the USB standard names both. The keyboard report it defines puts modifier keys in a byte of their own and six key codes after them, and the specification states the ceiling in those words: the limit is six non-modifier keys for a boot keyboard. So Shift, Ctrl and Alt never use up one of the six. The other ceiling is the wiring. When the combination pressed cannot be told apart in the key matrix, the standard has the keyboard report an error in every slot rather than guess, and that ghost key case is the one cheap boards run into at two or three. A keyboard can be held back by its wiring, by the report, or by both.
Is anything I type recorded?
No. Every key press is handled inside the page and discarded immediately. Nothing is sent to a server, saved to your device, or shared with anyone.
Is the Keyboard Test free, and does it need an install or admin rights?
Free, with no account, no email, no download and no extension. That last part matters on a work or school machine, where installing a diagnostic tool usually needs an administrator — this is a web page, so a locked-down laptop can run it exactly like any other.
Why not just type into a document to check the keys?
A document only shows the characters that arrive. It cannot show you a modifier that stays stuck down, or the function and media keys that produce no character at all. Those are most of the ways a keyboard actually fails. The exception runs the other way. A key that fires twice from one press — chatter, from worn contacts — is invisible here, because this page counts which keys arrive rather than how many times each one does, so a chattering key lights up and looks healthy. For that one symptom a document is the better tool: type the same character in short bursts and watch for doubles you did not ask for.