Reaction time test

How it works

1. Tap the box. It turns red.
2. After a random wait of 2 to 5 seconds, it turns green. Tap as fast as you can.
3. Do that five times. You'll get your average, your best try and how steady you were.

Tap while it's still red and that try doesn't count. You just go again. The same happens if you take longer than 2 seconds, or if your time is under 100 ms, because nobody reacts that fast to a color change. That's a lucky guess, not a reaction.

What's a good reaction time?

A typical result on tests like this is around 273 ms. My app uses the same words for each band as this page:

The "faster than about n% of players" line comes from a simple model centered on 273 ms. It's a rough guide, not a ranking of real people.

How this page times you, and what it can't see

I spent a lot of time on timing for my Android app, and this test follows the same approach as far as a browser allows. The switch to green happens inside a single animation frame, with no fade. The clock starts at the next frame, which is the earliest the green can actually be on your screen. Your tap is timed with the timestamp the browser gives the input event, so a busy page doesn't add delay.

Some delay is still out of reach. Your screen and the browser's compositor need a frame or so to show the green, and your mouse, keyboard or touchscreen needs a few milliseconds to report the press. Wireless mice and Bluetooth keyboards can add more. Some browsers also round their timers for privacy, and a few privacy modes round them a lot.

All of that can only make your time slower, never faster. It's also the same on every try, so compare your results on one device and one browser, not across devices.

Tips for steady results

• Sit comfortably and keep your finger just above the button, mouse or screen.
• Use the same finger and the same device each time.
• Don't try to guess the moment. The wait is random, and guesses end up as too early.
• Do a few runs. The first one is usually slower while you get used to it.

On your phone

Reaction Time is the Android app this test comes from. On a phone I can go further than a browser: it matches the exact screen refresh where the green appears and takes the touchscreen's own timestamp for your tap. It also has five more modes besides this one: start lights, go or no go, sound, vibration, and a 2 player duel on one phone. Your stats and a chart of your last 10 runs stay on your phone.

Questions

Why did my try count as too early?

Either you tapped while the box was still red, or your time was under 100 ms. Times that fast are anticipation, so they're thrown out.

Is a phone or a computer faster?

It depends on the device. Screens, touch panels and mice all add different amounts of delay, which is why results from different devices aren't a fair comparison.

Is my result saved?

Only your best average, and only in this browser. Nothing gets sent anywhere.