Input Lag Tester
Measure your end-to-end reaction time — the combined lag of your display, mouse or keyboard, and your own reflexes. Wait for the box to flip, then click or press Space as fast as you can. Take several goes for a reliable average.
Click to start
When the box flips, click or press Space as fast as you can.
Recent attempts
lower is betterInput lag is the delay between an action — a click or keypress — and its result appearing on screen. It spans the whole chain: your input device registering the press, the system processing it, and the display drawing the response. This test measures that chain plus its biggest link, your own reaction time.
After a random delay the box flips to a high-contrast state. The flip is timestamped at the exact frame it's painted, using the browser's animation frame clock, and compared to the timestamp of your click or keypress. Because the result bundles monitor response, input reporting, and reflexes, it's a real-world latency figure rather than a pure hardware number.
Most people land between 200 and 300 ms; trained gamers reach 150–200 ms. Pure visual reaction averages around 250 ms, and hardware adds another 20–70 ms — which is why a high-refresh monitor and a high-polling-rate mouse genuinely shave milliseconds, even though the human part dominates. Judge yourself on the average of several attempts: single tries easily swing by 50 ms.
How your result ranks?
| Result | Rank | What it means |
|---|---|---|
| Under 200 ms | Lightning fast | Elite territory — reflexes on par with competitive esports players |
| 200–250 ms | Great reaction | Faster than most; typical of regular gamers on decent hardware |
| 250–300 ms | Solid | Right around the human average for reacting to a visual change |
| 300–350 ms | Average | Perfectly normal, especially on a slower display or a trackpad |
| Over 350 ms | Keep practicing | Often fatigue, distraction, or a laggy setup rather than slow reflexes |