A ninety second timer

This page starts counting 90 seconds the moment it opens, and makes a sound when it finishes. Nothing to set, and nothing to press first.

What people set 90 seconds for

Rest between heavy sets, a microwave interval, or the pause a good argument deserves.

Worth knowing

Ninety seconds is roughly how long an emotional surge takes to pass through the body unaided — the reason "wait a minute and a half" is better advice than it sounds.

Questions

Do the timers keep running if I switch tabs?

Yes. The countdown is measured against a monotonic clock rather than counted in ticks, so a backgrounded tab, a throttled timer or a laptop lid closing does not lose time — when you come back it shows what it should, not what it managed to count.

Does a timer survive a daylight-saving change?

Yes, and the distinction matters. A countdown measures elapsed real time, so a timer set for six hours across a spring-forward still runs six real hours even though the wall clock advances seven. An alarm set for a wall-clock time does the opposite: it fires when the clock says so, which is what you want from an alarm.