—

Best single

—

Best median

0

Sessions

Press with a click, a tap, Space or Enter. The clock starts on the first frame that shows the signal and stops when you press, not when you let go. Screen and input delay are not included.

Next: Stroop Challenge, Schulte Table, Typing Speed Test.

  • 100% Free
  • No Sign-Up
  • No Credit Card
  • No Free Trial
  • No Pro Tier
  • No Watermarks

Nothing is uploaded. Just open it and start.

Test your reaction time

Free, no sign-up, no credit card, no trial. Wait for the signal and press to see your reaction time in milliseconds over five rounds, with your median and spread, or try the sound, choice, go/no-go and aim tests.

Millisecond precision

Reflexes measured with the browser's high-resolution timer — click the instant it turns green.

More than one test

Sound, choice and go/no-go reaction tests, and an aim trainer with target sizes, shrinking targets and a click map.

Median, spread and history

Five-round sessions with median, best and spread, lapses and false starts counted, and a daily tired-or-sharp check.

Private & client-side

No accounts, no leaderboards phoning home. Everything stays in your browser.

Related tools

Schulte Table

Schulte table trainer: number, letter and red-black grids, hard modes, progress chart, keyboard and screen reader play, share card.

Typing Speed Test

Measure typing speed, accuracy and consistency on timed runs of words, quotes or code, with a key heat map, history and challenge links.

Spin the Wheel

Spin a wheel to pick a winner from your own list. Weights and shown odds, secure randomness, share by link, ready-made wheels.

Fancy Text Generator

Turn plain text into bold, italic, cursive, upside-down and zalgo styles, keep emoji intact, check bio limits and copy in one tap.

Frequently asked questions

How does the reaction time test work?
A session is five rounds. The panel is red or blue (WAIT) for a random one to three and a half seconds, then changes (GO). Press as fast as you can: with a click, a tap, Space or Enter. Your time is measured from the first screen frame that shows GO to the moment you press, not when you let go. Your headline number is the median of the five, with your best and the spread.
What is a good reaction time?
Most people land between 200 and 300 ms for a simple visual reaction. Under 200 ms is fast and under about 160 ms is rare. Your screen and input device add delay that no web page can measure, so compare scores from the same setup rather than against other people's.
Why did it say “Too soon”?
You pressed before GO, or so soon after it (under 80 ms) that it can only have been a guess. That round does not count and is repeated; false starts are listed in your result.
What is a lapse, and why was a round cancelled?
A response slower than one second is a lapse of attention, so it is counted and shown but left out of your median. If you switch tabs or windows during a round it is cancelled, because a hidden page cannot show the signal fairly and the time away would otherwise be counted as a slow reaction.
What do Sound, Choice and Go / No-Go test?
Sound is the same test with a beep instead of a colour (kept apart from your visual records, and it needs sound effects on). Choice lights up the left or right side and you press that side (arrow keys or F and J on a keyboard). In Go / No-Go you press for the PRESS circle and hold back for the DON'T square. Choosing and holding back take longer than a simple press, so these times are higher.
Can I use it if I can't tell red and green apart?
Yes. Switch Colours to blue and yellow. The states are also written as words and shown with a hand or lightning symbol, and the Sound mode needs no colour at all. The text on every panel colour meets the 4.5:1 contrast guideline.
What's the aim trainer?
A 15, 30 or 60 second drill of clicking targets of three sizes, optionally shrinking and fading away. Your score combines speed and accuracy, you see your best streak, and a map shows where each click landed relative to the target centre so you can spot a habit of aiming too high or to one side. Each setup keeps its own best. It needs a mouse or a touch screen.
What does the daily check do?
After a session it compares today's median with the median of your last few days. If it is 15% or more slower than usual it says so, which can be a sign you are tired.
Is my data tracked?
No. The timing, your records and history stay in your browser's local storage, nothing is uploaded, and there are no leaderboards. It's free with no sign-up.

Spotted a bug or have a suggestion?

Found something broken, have an idea, or just want to say thanks about any of our tools? Every message reaches a real person.