Reaction Time Test
Tap the instant the screen turns green, and find out your average reaction time in milliseconds.
Measure now →Why test here
- No sign-up, no install — measured in the browser, results immediately.
- Average in milliseconds — several trials are averaged rather than judging you on one lucky tap.
- Restraint is tested too — red no-go trials require you not to tap, which measures response inhibition.
- Challenge a friend — share your result and see who is quicker.
- Records kept — your best stays on your device so you can watch it improve.
How the test works
Tap as fast as you can the moment the screen turns green. Tapping before it changes counts as a false start.
Occasionally the screen turns red instead — a no-go trial, where the correct response is to hold still. After several rounds your average reaction time in milliseconds is reported.
You will be quicker when rested and focused, looking at the screen with your finger already hovering. Typical simple visual reaction time is around 200–270 ms; under 200 ms is genuinely fast.
What a reaction time is made of
The gap between the screen changing and your finger landing is not one thing. It is several stages stacked together.
- Noticing — the change reaching your eye and registering as a signal.
- Deciding — telling a go signal from a stop signal. More options makes this longer.
- Moving — the decision travelling to your finger and the finger reaching the screen.
- The machine's share — how often the display redraws and how long touch input takes to arrive. Anything measured in a browser always includes this.
That is why the same person scores differently on different hardware. Simple visual reactions in adults are usually discussed in the 200–300 millisecond range, but that figure depends on how it was measured too — so the change in your own scores on one device is far more meaningful than a comparison with anyone else.
Holding still on red is the harder test
If it were only about hitting green quickly, the trick would be simple. The difficult half is not moving on red.
The more you prepare to fire, the further your hand has already committed, and from there a stop signal is hard to obey. Pressing when you should have waited is a false alarm, and the faster someone's average gets, the more of them tend to appear.
So a good result is a fast average with few false alarms. Shaving the average by launching early always comes with that bill attached.
Measuring yourself properly
- Warm up before you count a run. The first attempt or two goes to getting used to the screen and the button.
- Hold conditions steady. Device, finger, posture and screen brightness all shift the number.
- Trust the average, not your best single try. One lucky early press easily becomes your record; the average reflects your actual state.
- Compare tired against rested. Sleep, caffeine and time of day move this measure noticeably.
Frequently asked questions
- Is it really free?
- Yes. Every game is free and no account is needed.
- What counts as a normal reaction time?
- Simple reactions usually land between 200 and 270 ms. Age, alertness and your device's display latency all shift the number.
- Are there other brain games?
- Yes — flash memory, the Stroop colour test, memory cards, 2048 and more than thirty others.