TenSecondCheck

Reaction time test

Wait for the signal, then click or press a key as fast as you can. Five tries.

Runs in your browser only

You can also press any key instead of clicking.

Your tries

  1. 1 —
  2. 2 —
  3. 3 —
  4. 4 —
  5. 5 —

How the reaction time test works

Click the box to start. It turns red, which means wait. After a pause of between 1.2 and 4.5 seconds, it turns green. Click, tap or press any key as fast as you can. Your time appears and the next try starts on its own.

There are five tries. The pauses are random, so you cannot learn the rhythm. If you click while the box is still red, you get Too early! and that try starts again — a false start never counts towards your result.

You can use the mouse, the touch screen or the keyboard. Pick one and stick to it: they have different delays, and mixing them makes the numbers hard to compare.

Reading your result

Average is the mean of your five tries and the fairest single number, because one lucky or distracted try moves it only a little. Best is your fastest try.

Most people land somewhere around 200 to 300 milliseconds, but treat that as a rough guide rather than a measurement of you. The number on the screen is the time between the green colour being drawn and your press arriving in the browser, and several things besides your reflexes add to it:

  • The screen. A 60 Hz screen draws a new picture every 16.7 milliseconds, so the green can appear up to that much later than the moment it was ready. Faster screens reduce this.
  • The input device. Wireless mice, keyboards and touch screens each add their own small delay.
  • The browser and the computer. A busy computer or a laptop on battery can delay both drawing and input a little.

That is why comparing your times with someone else’s is fair only on similar equipment — and why the duel below gives both players exactly the same pauses.

Getting a result you can trust

  • Sit comfortably with your finger already resting on the button or key.
  • Close other heavy tabs and apps, and plug a laptop in.
  • Use a wired mouse or the keyboard if you can.
  • Do a practice round first. Your second and third runs are usually more consistent than the first.
  • Look at the box, not at the numbers. Watching the results between tries costs attention.

Your times will vary from try to try and from day to day. Tiredness, distraction and expecting the signal all move them. That is normal and is the reason the test takes an average.

Challenge a friend

After five tries, type your name if you want it shown and press Create the challenge link. Send the link however you like: where the browser supports it a Share button opens the system share menu, and you can always copy the link or send it through Telegram or WhatsApp.

Your friend sees your average and gets exactly the same pauses you had. The pauses come from a short code in the link, so neither of you gets an easier sequence. When they finish, both results appear side by side, compared on the average of five tries.

From there, your friend can send a rematch with both results in it, or start a fresh challenge for someone else.

Nothing about the duel is stored on a server. The name, the time and the pause code all live in the part of the link after the # sign, which browsers do not send to any website. That is also why a duel link keeps working for as long as someone has it.

If the test behaves oddly

  • The box turns green late or unevenly. The computer is busy. Close other tabs and try again.
  • Every result is unusually slow. Check for a wireless mouse with a weak battery, or a laptop in power-saving mode.
  • Key presses do nothing. Click the box once so the page has focus, then use the keyboard.

Want to know whether the delay is in your mouse rather than in you? Check the buttons with the mouse test. Players using a controller can check sticks and triggers with the gamepad test, and the keyboard test shows whether every key registers when pressed quickly.

Questions and answers

What counts as a false start?
Any click or key press while the box is still red. The try is not recorded and simply starts again with the same pause, so guessing never helps your score — it only costs you time.
Why am I slower on my phone than on my computer?
The test measures the whole chain, not just you. Touch screens take a moment to recognise a tap, and phones often run their screens and browsers in power-saving modes. Comparing results is fair only on the same kind of device.
Can someone cheat in a duel?
The result travels inside the link, so a determined person could edit it. The site rejects impossible values and damaged links, but the duel is a friendly game, not a verified competition. If you want a fair rematch, play the same link side by side.
Is my result or name stored anywhere?
No. Your times exist only in this tab. When you create a challenge, your name and average go into the part of the link after the # sign, which browsers never send to a server. The name you typed is remembered on this device only, to save you retyping it.
Is a faster time always better?
For this test, yes, but a single fast try means less than a steady average. Times far below what most people manage usually come from anticipating the signal rather than reacting to it, which is why guessing is punished as a false start.