This page opens with the timer already set to 5 minutes. Press Start or hit the spacebar and it begins; when time is up the alarm rings and the disk blinks. You can always drag the disk to a different time.
For short bursts, a shape beats digits. A 5-minute disk tells you what's left in one glance, so you keep moving instead of checking a clock.
A 5 minute timer is the go-to for Pomodoro breaks, soft-boiled eggs, and taking turns with kids.