Keyboard tester
Press any key — it lights up on the layout below and stays marked as tested, so you can check every switch on your board.
Press any key on your keyboard to begin. Keys light up while held and stay marked once tested.
Fn, media and some system keys are handled by the keyboard or OS and may never reach the browser.
How it works
- Click anywhere on this page, then press each key on your keyboard — every key that registers lights up blue on the drawn layout and stays marked as tested.
- Hold several keys down at the same time to test rollover: the counter shows how many keys your keyboard reports simultaneously.
- Watch the event log for keys that are not on the drawn layout, and click Reset tested keys to start a fresh pass.
Frequently asked questions
- How does the keyboard tester work?
- The page listens for the keyboard events your browser fires whenever a key goes down or up. Each event carries a physical key code, which the tool matches to the drawn layout to light the key up. Because it reads standard browser events, it works with any wired, wireless or laptop keyboard without installing anything.
- Why does one of my keys not light up?
- Some keys never reach the browser. The Fn key is handled inside the keyboard hardware, media keys are usually intercepted by the operating system, and keys like Print Screen or the Windows key can be captured by the OS before the event fires. If a normal letter or number key stays dark here and in a text editor, the switch itself is likely faulty.
- What is key rollover and ghosting?
- Rollover is how many keys a keyboard can report at once — cheap membrane boards often manage only two plus modifiers, while gaming keyboards advertise n-key rollover. Ghosting is when an unpressed key registers because of the matrix wiring. Hold down clusters of nearby keys and watch the simultaneous counter: if it stops climbing or a wrong key lights up, you have found your board’s limit.
- Are my keystrokes recorded or sent anywhere?
- No. Everything runs locally in your browser — there is no network request, no analytics on key data and no storage. Keystrokes are only used to update the display in front of you and are gone when you close the tab.
- Does it work with laptops and non-US layouts?
- Yes. The drawn layout is standard ANSI, and keys are matched by physical position, so a QWERTZ or AZERTY board still lights up the correct key — the live readout shows the actual character your layout produces. Keys that do not exist on the ANSI drawing, such as extra ISO or laptop keys, still appear in the event log below.
About this tool
A keyboard tester answers a simple question: does every key on this board actually work? Press keys one by one and each lights up on a drawn ANSI layout, then stays marked in a lighter shade so you can see at a glance which switches you have already verified. It is the quickest way to check a keyboard after a spill, to inspect a second-hand mechanical board before paying for it, to confirm a warranty claim about a dead switch, or to hunt down key chatter — a worn switch that intermittently drops or doubles its input.
The tool is built on the keyboard events every browser fires natively. Each press reports two things: a physical key code tied to the key’s position, which drives the lit-up layout, and the character your active layout produces, shown in the live readout together with any held modifiers. Everything happens locally in your browser — no download, no network traffic, and no keystroke ever leaves your device, which matters for something that by definition reads everything you type.
The simultaneous-keys counter turns the page into a rollover and ghosting test. Hold down growing clusters of keys — WASD plus Shift and Space is the classic gaming check — and the counter records the highest number your keyboard reported at once. Many office keyboards top out at six or fewer keys in unlucky combinations; if a key you are not touching lights up, you are seeing ghosting in the board’s switch matrix.
A few keys are invisible to any browser-based tester: Fn is processed inside the keyboard itself, and media or power keys are typically consumed by the operating system. Keys that exist but are missing from the ANSI drawing — ISO backslash, Japanese conversion keys, macro keys — still register in the event log, so nothing that reaches the browser goes unnoticed. Enable the Space and Tab blocker while testing so those keys do not scroll the page or move focus mid-test.