Is My Keyboard Lagging? A Step-by-Step Input Delay Test
Find keyboard input delay, missed keys and chatter with controlled browser tests before blaming the hardware.
Understand the board before you move
What the keyboard test checks
The tester shows whether your browser receives every key press: letters, numbers, modifiers, F-keys, navigation cluster, arrows and the numpad. Each key lights up while held, stays tinted once seen, and carries its own press counter — so a dead, bouncing or chattering switch is obvious in seconds.
Find broken or chattering keys
Press each key once, slowly, and watch the counters: a key that counts twice per press is chattering (switch bounce), a key that never lights up may be dead, remapped or blocked by software. Sticky keys show up as a highlight that never turns off.
Rollover and ghosting (NKRO)
Hold several keys at once and check Max at once . Budget keyboards often register only 6 keys plus modifiers (6KRO); gaming keyboards with N-key rollover register everything. If a combination refuses to register, that's ghosting — a matrix limitation, not a broken key.
Full-size, TKL and 60% views
Switch the on-screen layout to match your board: full-size with numpad, tenkeyless, or compact 60%. Counters carry across views, and keys that exist only on bigger layouts still count — the last key readout shows every code your keyboard reports, including media keys.
Rules and decisions that matter
What is this keyboard test?
A free online keyboard tester: press any key and the matching key lights up on a virtual keyboard, with a per-key press counter, a total counter, a rollover check and a log of the last keys pressed. No download needed.
How do I find a broken key?
Press every key once. A key that doesn't light up isn't reaching the browser — it may be dead, remapped or blocked by software. A key that counts twice per press is chattering and its switch likely needs cleaning or replacement.
What does "Max at once" mean?
It's your rollover result: the highest number of keys the keyboard reported as held simultaneously. 6 is typical for office boards (6KRO); gaming keyboards with NKRO can register far more.
Why doesn't the Windows key stay blocked?
The operating system handles some keys (Win/Cmd, media keys, Fn) before or outside the browser. The test still counts what the browser receives, but it can't stop the OS from acting on them.
A browser keyboard test sees the keyboard events delivered by the operating system. System shortcuts, firmware layers and browser-reserved combinations can prevent a key event from reaching the page. MDN KeyboardEvent.
Common mistakes and how to correct them
The fastest-looking move is often not the safest. Scan the whole board, protect working space, avoid spending recovery tools too early and review the exact move that created the problem.
Turn the ideas into a repeatable practice routine
Play slowly for three rounds. Before every action, name the goal of the move, the space it creates and the next move it enables. Then replay at normal speed without abandoning that check.
The most useful details to remember
Why gamers test their keyboard
Movement, ability combos and push-to-talk all fail silently when a switch degrades. A quick pass before a session confirms WASD, Shift, Space and your macro keys all register — and the rollover check proves your combos physically can't drop inputs.
Cleaning and troubleshooting
Dust and debris under a keycap cause missed or repeated presses; compressed air and a keycap pull often fix it. If a key fails in every app and this test, try another USB port, disable vendor software remaps, and on mechanical boards consider swapping the switch.
Keyboard Test
Play nowFrequently asked questions
What is this keyboard test?
A free online keyboard tester: press any key and the matching key lights up on a virtual keyboard, with a per-key press counter, a total counter, a rollover check and a log of the last keys pressed. No download needed.
How do I find a broken key?
Press every key once. A key that doesn't light up isn't reaching the browser — it may be dead, remapped or blocked by software. A key that counts twice per press is chattering and its switch likely needs cleaning or replacement.
What does "Max at once" mean?
It's your rollover result: the highest number of keys the keyboard reported as held simultaneously. 6 is typical for office boards (6KRO); gaming keyboards with NKRO can register far more.
Why doesn't the Windows key stay blocked?
The operating system handles some keys (Win/Cmd, media keys, Fn) before or outside the browser. The test still counts what the browser receives, but it can't stop the OS from acting on them.
Do F-keys, Tab and the spacebar work in the test?
Yes — the page suppresses their normal browser actions (scrolling, focus jumps, menus) while you test, so you can safely check every key. Refresh (F5) and browser fullscreen (F11) keep working.