Keyboard Tester
Press every key on the US ANSI layout and watch it light up live in your browser. Keydown and keyup states, hold times, and rollover checks, all on your machine. Nothing is uploaded.
How to use
- Click anywhere on the page, then press keys on your keyboard. Each key lights up while it is held and goes dark again when you release it.
- Read the tiles under the layout: how many keys are held down right now, how many presses were counted in total, how long you held the last key, and the most recent keydown or keyup event.
- Test rollover by holding several keys at once. The keys that never light up together are combinations your keyboard cannot report; many membrane keyboards drop some once a few keys are held.
- Reset the counters with the button under the layout when you want a clean run.
Frequently asked questions
Does this keyboard test upload anything?
No. Key events are read inside your browser tab and nothing is recorded, stored, or sent anywhere. The page sets no cookies. Ad slots on the page are served by third-party networks, which follow their own privacy policies.
Does this measure keyboard latency?
No, and be careful with any web page that claims to. This tester shows your input echo: which keys the browser receives, when they go down and up, and the time between those events. True end-to-end latency, from the physical switch travel to a pixel changing on screen, involves hardware and display delays that a browser tab cannot see.
Why does my Fn key never light up?
On most laptops the Fn key is wired to the keyboard's embedded controller, which rewrites the key before the operating system ever hears about it. The browser receives only the rewritten result, such as F1 or a media key. A few keyboards do pass Fn through; whether it lights up here depends entirely on your hardware.
Why does a key stay lit, or never light up?
A key that stays lit usually means the system still thinks it is held down, which can happen when a keyboard shortcut steals the keyup event. Press the key once more or reset the counters to clear it. Keys that never light up point to rollover limits: many membrane keyboards can report only a handful of simultaneous keys, so some combinations are dropped before they reach the browser.
Which browsers work?
All current browsers report keydown and keyup events with a physical key code, which is all the tester needs. Some keys belong to the browser itself, though: F5, F11, and most Ctrl, Alt, and Win shortcuts are handled by the browser or operating system and may never reach the page.