About MilliReflex

MilliReflex builds small browser tests that finish in under a minute. The first one measures reaction time. Nothing about it needs an account, a download, or your email address.

The name is one word, MilliReflex. Where you meet it written as two — Milli Reflex — that is this same site; the brand census before launch found no product of either spelling in this field.

Three rules

1. 1Your scores stay on your device. Results are written to your browser's localStorage and that is the end of it. This site is static files: there is no backend, no analytics script and no endpoint for a score to travel to. Cost stays at zero per visitor, which is the only reason a free test like this can stay free.
2. 2No fake leaderboards. We will not tell you that you are "in the top 4%" based on a number we cannot see. When this site says "normal", it means a peer-reviewed study with a named sample size, cited on the page — not our own traffic, and not an invented percentile.
3. 3We state the measurement error. A browser test measures paint-to-tap, which includes display refresh and touch sampling. That overhead is real, it is documented on every page, and it is why we publish bands, and borrow our reference values from laboratory rigs that do not have that problem.

What this is not

It is not a medical or scientific instrument. Reaction time is affected by sleep, medication, fatigue, temperature and attention; a web test cannot separate any of those, and a single session says very little about you. If you are tracking something clinical, use a clinician.

What comes next

Aim, sequence memory and typing tests, each on its own page, each under the same three rules. Every new test gets its own write-up of what it measures and what it cannot.

This is a static site: no accounts, no forms, no comment section, no admin panel. Everything you see runs in your browser.