ReactionTest

Sooner or later somebody claims to have the quickest reflexes in the room, and you need a way to settle it. ReactionTest is a free browser test for that sort of thing, with no account or download. You press start, wait for the background to turn green, and click or tap as soon as it does. It runs five rounds and then shows your best time and your average in milliseconds.

The site explains the five rounds plainly. The first try is often slow because it catches you off guard, so an average of several attempts says more than any single click.

Below the test there's a small reference table of typical visual reaction times by age, roughly 190 to 250 ms for people aged 18 to 30 and 250 to 350 ms for people over 50. That gives a result some context without turning it into a diagnosis. The project calls it a casual challenge rather than a medical assessment, which is the right way to read it.

The same site has a click-speed test with timers from 1 to 120 seconds and a spacebar test. Sequence Memory, Number Memory and an Aim Trainer round things out. They're all short, browser-based drills, handy for warming up before a game or settling an argument about who's quicker. The interface comes in ten languages.

Hardware matters more than the site can control. Its FAQ says the test accounts for display lag and input delay, but that results still vary with your device, browser and connection. Compare scores taken on the same setup.

There's no sign-up. The privacy policy, dated December 2024, says test results and settings stay in your browser's local storage, lists IP address and browser details among the technical data it collects, and names Google Analytics. The home page also loads Google's ad script, which the policy doesn't mention.

Neither the policy nor the terms name a person or company behind the site, only contact addresses at the domain. If you fancy a friendly contest over who's quicker, it's a fun one to pass around.