Reaction Time Test

Click when the screen turns red, then click again the instant it turns green. After five rounds you get your average reaction time in milliseconds, how consistent you were, and how you compare.

Round: 0/5
Last: —
Average: —
Best average: —

Click to startWait for the screen to turn green, then click as fast as you can. Five rounds.

Mouse, touch, Space or Enter

How the reaction time test works

Click the box (or focus it and press Space). It turns red and the test waits a random time between 1.5 and 4.5 seconds, so you cannot predict the moment.
As soon as the box turns green, click. Your time is measured from the frame in which the green colour is drawn to the moment the browser receives your click.
Repeat five times. Clicking during the red phase is a false start and the round is replayed.
The summary shows your average, best and worst round, the spread between them and a bar for every round. Your best average is kept as a personal record.

What affects your result

The number you see is not only your nervous system. It is the total delay of a chain of hardware and software, and each part adds a little:

Monitor refresh rate. A 60 Hz screen draws a new image about every 16.7 ms, a 144 Hz screen about every 6.9 ms and a 240 Hz screen about every 4.2 ms. A faster display shows the green frame sooner on average.
Display processing. TVs and some monitors add extra input lag with image processing. Game mode or a monitor marketed for low latency helps.
Mouse and connection. Polling rate, switch type and the wireless link all add a small delay. Modern gaming wireless mice are generally very close to wired ones; cheap Bluetooth mice can be noticeably slower.
Browser and system load. Background downloads, many open tabs or power-saving modes can delay frames. Close heavy apps and keep your laptop plugged in.
You. Tiredness, attention, age and warm-up all matter. Caffeine may help a little when you are tired, but sleep makes a bigger difference than any drink.

How screen refresh adds latency

When the test changes the colour, the green frame can only appear at the next screen refresh. On average that wait is about half a refresh interval, and the monitor itself then needs time to switch its pixels. That is why the same person often scores a few milliseconds faster on a high refresh rate monitor. You can check what your display actually runs at with the refresh rate test.

How to improve your reaction time

Rest your finger lightly on the button so it only has to press, not travel.
Look at the centre of the box and stay relaxed. Tension makes you slower and causes false starts.
Warm up with a couple of runs before you compare results. Most people improve over the first few attempts.
Play in short sessions. Results get worse when you are tired or bored.
Practise with targets too: the aim trainer combines reaction speed with accurate mouse movement, which is closer to what games ask for.

Frequently asked questions

What is a good reaction time?

For a simple visual test like this one, most people average somewhere around 200 to 300 milliseconds. Averages under 200 ms are fast, and results in the 150s and 160s usually come from practised players on a fast, low-latency setup.

Why is my result slower than in games?

This test measures everything between the screen changing and your click arriving: your own reaction, plus the delay of your display, browser and mouse. Games can feel faster because you often anticipate what is about to happen instead of reacting to a surprise.

Why does the test use five rounds?

A single click can be lucky or unlucky by 50 ms or more. The average of five rounds is a much steadier number to compare with your earlier results or with friends.

What happens if I click too early?

Clicking while the screen is still red counts as a false start. The round is not scored and has to be repeated, so guessing never improves your average. The number of false starts is shown in the summary.

Can I use the keyboard or a phone?

Yes. Click the test area once to focus it, then press Space or Enter when it turns green. On a phone or tablet, just tap. Touch screens usually add a little extra delay compared with a good mouse.

Is my personal best saved?

Your best five-round average is stored only in this browser, using local storage. Nothing is uploaded, and clearing your browser data removes it.

More free tests

Aim trainerHit 30 targets as fast as you can. Score, accuracy and time per target, in the browser.Sound reaction time testClick the moment you hear a beep. Compare how fast you react to sound and to what you see.Choice reaction time testLeft or right? React to the arrow with the correct key — speed and accuracy both count.Target reaction testA target pops up at a random spot — find it and click it as fast as you can.CPS testHow many clicks per second can you do? 1, 5, 10, 30 and 60 second modes with click rhythm stats.Mouse testCheck every mouse button, the scroll wheel and side buttons, and catch a faulty double click.