Why was my try cancelled?

If you click while the screen is still red, the round is voided. That stops you from clicking early and getting a fake-fast time, since the test only counts the gap after the colour actually changes.

How can I get faster?

Rest, focus and a steady hand help most. Sit ready, watch the centre of the box rather than staring, and click the moment you sense the change instead of waiting to be sure. Practice trims a little, but reaction time has natural limits.

Are my best scores saved?

Your best result for each game is kept in your browser so you have something to beat next time. It lives only on this device, so clearing your browser data or switching to another device starts you fresh. Nothing is tied to an account because there is no account.

Does anything I do here get sent to a server?

No. Every game runs locally in your browser. Your scores and any text you type stay on your own device, nothing is uploaded, and nothing is logged or stored by us. Once the page has loaded it keeps working even if you go offline.

Reaction Time Test

Wait for the screen to turn green, then click as fast as you can. This free reaction time test measures the gap between seeing the change and reacting, in milliseconds, and averages five tries for a fair number. Most people land somewhere around a fifth of a second; sleep, caffeine and practice all move it. Nothing is uploaded and there is no sign-up.

No sign-up, ever
100% free
Nothing uploaded
Works offline after first load
Scores stay on your device

Read the guide: What Is a Good Reaction Time?

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Best: —

How to use it

1
Click to start

Click the box and wait. The screen stays red until a random moment, so you cannot predict it.
2
React on green

The instant it turns green, click. Click too early on red and that try is voided so you cannot game it.
3
See your average

After five rounds you get your average time in milliseconds, plus your best single click.

When it comes in handy

Gaming warm-up

Loosen up your reflexes before a session and see whether you are sharp or sluggish today.

Track your day

Check how tiredness, coffee or a break changes your numbers over the course of a day.

Friendly contests

Pass the device round and see who has the quickest trigger finger.

Instant & 100% private — nothing is uploaded

Every game runs right here in your browser, and your best scores are kept on your own device. Nothing is sent to a server, so there is no sign-up and no account. Load the page once and it keeps working even if you go offline.

Frequently asked questions

What is a good reaction time?: For a simple click-on-green test like this, a typical result sits around 250 to 300 milliseconds. Under about 250 ms is quick, and anything near 200 ms is very fast. Your screen and mouse add a little delay, so treat the number as a fair comparison with yourself rather than an exact figure.
Why was my try cancelled?: If you click while the screen is still red, the round is voided. That stops you from clicking early and getting a fake-fast time, since the test only counts the gap after the colour actually changes.
How can I get faster?: Rest, focus and a steady hand help most. Sit ready, watch the centre of the box rather than staring, and click the moment you sense the change instead of waiting to be sure. Practice trims a little, but reaction time has natural limits.
Are my best scores saved?: Your best result for each game is kept in your browser so you have something to beat next time. It lives only on this device, so clearing your browser data or switching to another device starts you fresh. Nothing is tied to an account because there is no account.
Does anything I do here get sent to a server?: No. Every game runs locally in your browser. Your scores and any text you type stay on your own device, nothing is uploaded, and nothing is logged or stored by us. Once the page has loaded it keeps working even if you go offline.