Pulse (dle.wtf)

Pulse asks one question: how well can you measure time without a clock? After a ready, set, go, an orb glows for a moment with a soft tone. When the screen says your turn, you press and hold anywhere, or hold the Space bar, and let go when it feels like the same length. The game then shows the pulse and your hold side by side to the hundredth of a second.

Each round scores up to 10 points, based on the ratio between your hold and the pulse, so holding twice as long costs as much as holding half as long. Being 10 percent off still scores about 9; being 50 percent too long drops to about 1. Five rounds give a total out of 50.

The Daily mode gives every player the same five pulses, mixing quick blinks with long holds from half a second to six seconds, with no clock and one attempt. New pulses arrive at 00:00 UTC. Easy practice uses pulses from 1 to 3.5 seconds and shows a running clock while you hold, and Hard practice uses the daily rules; after a practice game you can send a friend a link to the same five pulses.

If the tab is hidden mid-round, that round starts again, and presses shorter than 60 milliseconds count as a tap rather than a hold. Stats for daily and practice games are kept in the browser.