Emoji reaction time

What the number actually measures

A healthy adult sees a change and reacts in roughly 200 to 250 milliseconds, and that is before any of this page is involved. What you get here is that reaction plus the screen's own refresh, the browser's event timing and whatever your input device adds, which is why the same person scores differently on a phone and on a desktop with a wired mouse.

So compare your times against your own, not against a table on the internet. The average over 5 rounds is the honest half of the result: 1 lucky round says nothing, and 5 of them say roughly where you are today.

Nothing here is sent anywhere

The timing, the average and your best all happen in this tab. The best is remembered on this device so it is there when you come back, and clearing your site data clears it. There is no account, no score table, and nothing to upload.