Skip to the timer
minute·timer

Naps and winding down

Sleep timer

Thirty minutes, running quietly. Use it to cap a nap before it turns into a deep sleep, or to give yourself a fixed wind-down before bed.

Wind down

30:00

Shortcuts: space start or pause · R reset · F fullscreen. The alarm rings even if you switch tabs.

In short

A nap of 10 to 20 minutes keeps you in lighter sleep, so you wake without grogginess; 30 minutes often cuts into deep sleep and 90 minutes completes a full cycle. NASA research on long-haul pilots found a planned nap averaging 26 minutes improved performance by 34% and physiological alertness by up to 54% relative to fatigued pilots who did not rest.

Default
30 minutes
Power nap
10 to 20 minutes, no grogginess
NASA nap
About 26 minutes
Full sleep cycle
90 minutes
Avoid
The 30 to 60 minute middle, which usually wakes you mid-cycle

Nap lengths, and why they matter

LengthWhat you get
10–20 minThe power nap. Light sleep only, so you wake up clear
30 minOften grogginess on waking, as you are cut off mid-deep sleep
60 minGood for memory, but expect to feel rough for a while afterwards
90 minA full sleep cycle, so you wake at a natural point

Twenty minutes and ninety minutes are the two lengths that avoid waking mid-cycle. The awkward middle is where the fog comes from.

A wind-down that actually ends

The other use for this page is the half hour before bed. Set thirty minutes when you start reading, or when you sit down with a series, and the alarm becomes the decision you already made rather than one you have to make at midnight.

Keep the screen dim, press Fullscreen so nothing else is on the display, and turn the sound down — the alarm only needs to be loud enough to notice, not loud enough to jolt.

Not a white noise player

This page counts down and rings; it does not play music or fade audio out. If you want music to stop after a while, most music and podcast apps have their own sleep timer built into the playback settings.

Questions about the sleep timer

Will the timer work if my phone screen is off?

Yes. The countdown runs against the device clock, so locking the screen does not stop it, as long as the tab is still open and the phone is not fully powered down.

What is the best nap length?

Twenty minutes for most people, most days. Ninety if you have the time and are genuinely short of sleep. Avoid napping late in the afternoon if you struggle to fall asleep at night.

Can I pause and come back to it later?

Yes. The same button pauses and resumes, and the space bar does both. Pausing holds the exact remaining time until you start it again.

Is there an app to install?

Not one you need. The page runs in any browser, though you can add it to a phone or tablet home screen if you would rather it opened like an app.

Sources

  1. Rosekind, M. R., Smith, R. M., Miller, D. L., Co, E. L., Gregory, K. B., Webbon, L. L., Gander, P. H. & Lebacqz, J. V. (1995). Alertness management: strategic naps in operational settings. Journal of Sleep Research, 4(S2), 62–66. The 34% and 54% figures compare napping pilots with a fatigued no-rest group, not with a well-rested baseline.