How does the reaction time test work?
Tap the instant the screen turns from red to green and you get your reaction time in milliseconds. It runs five times and shows your average. Tap before green and you get "Too soon!" and that try is repeated.
The red screen waits a random 1.5 to 5 seconds every time, so you cannot learn the rhythm and tap early.
Which tests are there?
| Test | How | Score |
|---|---|---|
| Color change | Tap when red turns green, 5 times | Average ms (lower is better) |
| Aim trainer | Hit 30 targets as they pop up | Average ms per target, accuracy % |
| Sound reaction | The screen stays the same. Tap when you hear the beep, 5 times | Average ms |
| Number memory | See a number briefly, type it after it disappears. Starts at 3 digits and grows by one | Longest number you got right |
What is an average reaction time?
Simple visual reaction time is commonly said to be around 200 to 300 ms. Reactions to sound are generally thought to be a little faster, and age, tiredness and focus make a big difference from person to person.
For number memory, most people are commonly said to hold about 7 digits at once. The labels in this game (Fast, Typical range and so on) are just for fun and are not a medical test.
Why do scores differ between devices?
Your score includes a little display and device lag, not just your hand. The game timestamps your tap right away with the browser's high resolution clock (performance.now), but it cannot remove screen delay.
- Refresh rate: a 60 Hz screen redraws about every 16.7 ms, so green can take that long to appear. 120 Hz and 144 Hz screens have a small edge.
- Mouse and touch: wireless mice and touch screens can add a few to a few dozen ms.
- Sound test: Bluetooth earbuds play sound late and make you look slower. Wired earphones or the device speaker are more accurate.
- Compare fairly: when you challenge a friend, use the same device.
How can I get a faster time?
- Look at the center. You notice the color change with your whole field of view, so keep your eyes still.
- Rest your finger on the key. Hover over Space or the mouse button so there is less to move.
- Do not guess the timing. The wait is random, and guessing gets you "Too soon!".
- On targets, aim first. Missed clicks only cost time. Move your eyes to the next target early.
Best scores and your last 10 results for each test are saved in this browser and shown as a bar chart. Use Share result to send your score to friends.