Human Performance Test

Today's challenge

How the daily challenge works

One test is featured every calendar day. The pick is derived from the UTC day-of-year, so everyone worldwide sees the same challenge on the same day, and it cycles through all fourteen tests rather than favouring the same few. Play it from the button above, then come back — your attempts are counted automatically from your local history and your personal best is shown for comparison.

Nothing is sent anywhere. The date on this page is calculated in your browser from your system clock, the featured test is chosen locally by the same rule every time, and your score comes from the history this site already keeps in your browser. There is no account and no server involved.

Getting a fair comparison

A daily result is only meaningful against your own previous ones, and only if the setup has not changed. Three habits make a daily series worth keeping:

1. Keep the setup fixed. A day on a wired mouse and a day on a Bluetooth keyboard are not comparable, and the gap is larger than most day-to-day changes. If you must switch devices, treat it as a new series rather than a continuation.
2. Test at a similar time. Reaction time is genuinely affected by alertness, and a late-night attempt is not a fair comparison with a rested morning one.
3. Discard the first attempt. Repeated measurement produces a real but short-lived improvement that arrives almost entirely in your first two tries, so a first attempt is a warm-up rather than a result. Seewhy practice plateaus.

With those three in place, a daily result becomes a series you can actually read. Without them, the day-to-day noise is larger than most of the differences you are looking for — which is the main reason a single score tells you very little on its own. Theaveraging explainer covers the arithmetic behind why.

Because the test changes daily, scores do not compare

Monday's reaction time and Tuesday's CPS are different quantities measured on different scales, and this page's "attempts today" counter applies only to the featured test. A better score on a harder test is not progress.

What does carry over is the method: which input device, how many attempts, whether you discarded a warm-up, how long since you last tested. Keeping those consistent across a rotating test set is more useful than chasing a single number, and each test keeps its own history so you can still compare like with like whenever the same test returns.

For the full picture of what each test actually measures, themethodology page documents the scoring rules and constants for every mode.

All tests