Guide
Device latency and reaction tests
Browser reaction tests are useful because they are easy to repeat, but every device adds a little delay between the visual signal and the recorded input.
What can change your score
- Display refresh rate changes how quickly lights-out appears on screen.
- Touchscreens, trackpads, keyboards, and mice each have different input delay.
- Browser load and background tasks can add timing noise.
- Battery saver modes can make animations and input feel less responsive.
How to compare fairly
Use the same device, browser, and input method when you compare scores. If you switch from a phone tap to a wired mouse, treat the result as a new baseline rather than a direct improvement.