20 Minute Timer

The short answer

A 20 minute timer counts down 1,200 seconds and rings at zero. Press Start above; it keeps time in a background tab and after a reload. Twenty minutes is a popular nap window: in one sleep study, a 10-minute nap helped at once, while a 30-minute nap left people groggy at first.

What fits in 20 minutes?

Twenty minutes is long enough for a proper session of something, and short enough to fit in a lunch break.

• A short afternoon nap. In a sleep lab study after a short night, 10 minutes of nap sleep helped straight away, 20 minutes helped from about half an hour later, and 30 minutes caused grogginess first. The study counted minutes asleep, so leave a few minutes to drift off.
• A 20-minute walk. Five of these a week is 100 of the 150 weekly minutes the CDC suggests for adults.
• A study round with a break. Study for 20 minutes, then take 5. In one study, fixed breaks like this went with less fatigue than taking breaks whenever you felt like it.
• Cook a simple dinner. One pan, three ingredients. Ideas in what to cook when you don't feel like cooking.
• Wind down before bed. Dim the lights, set out tomorrow's things, read on paper. See how to build a bedtime routine.

How to use the 20 minute timer

1. Press Start. The timer is already set to 20 minutes. The space bar starts and pauses it too.
2. Need a different time? Type it in the box, such as 7, 7m 30s or 7:30, and press Set. Or tap another preset.
3. Make it big. Full screen (or F) shows only the countdown. Kids view shows a big colored disk that shrinks as time runs out.
4. When it rings, press Stop alarm or the space bar. Restart runs the same 20 minutes again; +1 min snoozes for a minute.

The timer saves the moment it will end on your device, so it stays accurate in a background tab and after a reload, and the time left shows in the tab title. The page has to stay open for the alarm to play.

Frequently asked questions

How long should a power nap be?

Short. In a study of naps after a short night, 10 minutes of sleep improved alertness right away, 20 minutes helped from about 35 minutes after waking, and 30 minutes caused grogginess first. The study counted time asleep, so set the timer a few minutes longer than the sleep you want.

Will the 20 minute timer wake me if my phone locks?

Not reliably. A locked phone pauses web pages, so the alarm may not play. The timer asks your screen to stay awake while it runs; for a nap, keep the phone plugged in with the page open, or use your phone's clock app as the safer alarm.

Is 20 minutes a good study block?

It is a good length for starting when focus is low. In a study of 87 students, fixed schedules such as 24 minutes of study and 6 minutes of break went with less fatigue than self-timed breaks. Once 20 minutes feels easy, try 25 or 50.

Sources and evidence

1. Brooks and Lack (2006): Which nap duration is most recuperative? — After a short night, a 10-minute afternoon nap improved alertness and performance at once; a 20-minute nap helped from about 35 minutes after waking; a 30-minute nap caused grogginess first, then helped.
2. CDC: Adult activity, an overview — Adults need 150 minutes of moderate-intensity activity a week, for example 30 minutes a day, 5 days a week, and it can be broken into smaller chunks.
3. Biwer et al. (2023): Comparing Pomodoro breaks and self-regulated breaks — Among 87 university students, fixed breaks (such as 24 minutes of study and 6 of break) went with less fatigue and more concentration than self-timed breaks, with similar work done.

Updated September 27, 2026.