Reaction Time Test

Measure how quickly you respond to a visual signal. Five attempts give you a far more reliable number than one.

Click or press Space to startWait for the screen to turn green, then react as fast as you can.

–Last (ms)

–Average (ms)

–Best (ms)

0Attempts

How the test works

The pad turns red and asks you to wait. After a random delay of roughly one and a half to four and a half seconds it turns green, and a timer starts at that instant. The moment you click, tap or press Space, the timer stops and your time is shown in milliseconds. If you react before the colour changes, the attempt is cancelled, because a guess is not a reaction. The random delay matters: if the wait were fixed you could learn the rhythm and anticipate it, which measures prediction rather than reaction.

What your number means

Most healthy adults land somewhere between about 200 and 300 milliseconds on a screen-based test. Numbers below 200 ms are rare on a normal display and often come from anticipation, so treat a single very low result with suspicion. Your average over five or more attempts is the figure worth tracking. Note that this tool measures the whole chain: your eyes, your brain, your hand and finger, your input device, your screen refresh rate and your browser. On a phone with a 60 Hz screen, the display alone can add up to about sixteen milliseconds of uncertainty; on a gaming monitor the same test can look slightly faster without you being any quicker.

Why your results vary

Fatigue and focus. A tired or distracted player is measurably slower. Test when you are alert.
Device and input. Wired mice and keyboards usually add less delay than wireless or touch input. Touchscreens often add noticeable latency.
Display. Higher refresh rates show the green signal sooner.
Browser load. Many open tabs can delay the timer. Close them for a cleaner reading.

How to improve your reaction time

Raw neural speed changes little with practice, but the parts around it do. Sit in a comfortable position with your hand resting on the input device so that no movement is wasted. Keep your eyes soft and watch the whole pad instead of staring at one point. Sleep, hydration and short breaks make a bigger difference than any trick. Our guide on improving reaction time and hand-eye coordination covers the habits in more detail, and the aim trainer lets you practise reacting and moving at once.

Is this test scientifically exact?

No. It is a fun, honest browser measurement, not a clinical instrument. Browsers schedule timers with small delays, and every device adds its own latency. It is useful for comparing yourself with your own earlier results on the same device, and less useful for comparing with other people on different hardware. Nothing you do here is stored or sent anywhere; the results disappear when you close the page.

Frequently asked questions

Why does the test say I clicked too early?

You clicked while the pad was still red. Wait for the colour to change; the delay is random on purpose.

Does the test work on a phone?

Yes. Tap the pad. Touch screens add a little delay, so expect numbers slightly higher than with a mouse.

Is my data saved?

No. Results stay in the page and are cleared when you leave or press Reset.