The Reaction Time Test measures how quickly you respond to a visual signal. Click to start, wait for the panel to flash green, and click again as fast as you can — the tool reports the gap in milliseconds and tracks your best and average over repeated attempts.
How it works
When you start, the panel waits a random amount of time (between roughly one and four seconds) before turning green. That randomness stops you from guessing the timing. The moment it goes green, a high-resolution browser clock starts; it stops the instant you click, and the difference is your reaction time.
If you click while the panel is still red, that counts as a false start and the attempt resets — no peeking ahead.
What the numbers mean
- Last — your most recent attempt in milliseconds.
- Best — the fastest single attempt this session.
- Average — the mean across every attempt, which smooths out flukes.
Average human visual reaction time is around 200 to 250 ms. Display refresh rate and mouse input lag both add a few milliseconds, so a wired mouse and a full-screen window give the most consistent results.
Tips for a faster time
Focus only on the panel, keep your finger resting lightly on the button, and run several attempts in a row — fatigue and distraction both slow you down, and the average is far more meaningful than any one lucky click.