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Nap timer with a gentle wake-up
Choose a 10, 15 or 20-minute nap and lie down. When it's time, a soft bell starts quietly and grows louder over about a minute and a half.
Timer
15:00
5 minutes to fall asleep, then a 10-minute nap.
Turn the media volume up and press Test the sound first. Keep this tab open: closing it, or another app playing sound, stops the bell. For a wake-up you can't miss, set your phone's alarm too.
Can't nap today? A short guided rest you stay awake for.
NSDR keeps you awake, so it can leave you less groggy than waking from a long nap. Afternoon Slump Reset runs about 11 minutes. Voice: Thorne (synthetic). Don't listen while driving or operating machinery.
11 min · free · no account
How the nap timer works
Pick how long to nap and how long you usually take to fall asleep. The timer adds the two, because the nap lengths in the research count minutes asleep, not minutes lying down. If you're not sure, leave it at 5 minutes.
Press Start and the page plays one sound file, made in your browser: silence for the nap, then a soft two-note bell. It starts quietly and gets louder and closer together for about a minute and a half, then rings for about 30 seconds more. There's no ticking, and nothing to download.
Press Test the sound before you lie down, so you know it's loud enough to wake you. Then put the phone face down. On most phones you can lock the screen too; on iPhone, keep Safari open on this page.
What the research says
A 10 to 20 minute nap helps after a short nightHolds up
In a 2006 study of 24 young adults who'd slept about 5 hours, 10 minutes of sleep lifted alertness and performance as soon as people woke, and some of the benefits lasted up to 155 minutes. After a 20-minute nap the benefits took 35 minutes to show, and a 30-minute nap brought a spell of grogginess first. That grogginess is sleep inertia. It's strongest when you wake from deep sleep, and without major sleep loss it rarely lasts beyond 30 minutes. The 2006 study was small and tested good sleepers who didn't usually nap, so treat the exact minutes as a guide.
- 1.Brooks A, Lack L (2006). A brief afternoon nap following nocturnal sleep restriction: which nap duration is most recuperative? Sleep 29(6):831-40. PMID 16796222.
- 2.Tassi P, Muzet A (2000). Sleep inertia. Sleep Med Rev 4(4):341-53. PMID 12531174.
- 3.Boukhris O, Suppiah H, Driller M (2026). Comparing the effects of a short nap and non-sleep deep rest on perceptual, cognitive, and physical performance in active adults. Clocks and Sleep 8(3):52. PMID 42783005.
Why the timer stops at 20 minutes
In the 2006 study, the 30-minute nap was the one that brought a spell of grogginess straight after waking, and grogginess is strongest when you wake from deep sleep. So the timer tops out at 20 minutes of sleep. Even then, give yourself a few minutes before anything that needs quick reactions.
Our guide to napping without feeling groggy covers the rest: when in the day to nap, and what helps you come round.
Using it with your phone locked
The bell is the end of one long audio file that starts when you press Start, so it doesn't depend on the page staying awake. Phones keep playing a web page's audio with the screen locked, the way music keeps playing, so on most phones you can lock the screen once the timer is running.
On iPhone, Safari has limits a web page can't get round. The bell plays at your media volume, and a page can't turn that up for you. Closing the tab, swiping Safari away, or starting other sound (music, a video, a call) stops it, and it won't start again on its own. A web page also can't ring like the Clock app's alarm.
On Android, Chrome works the same way. Some battery saver modes stop background audio, so try it once with the screen off.
The surest way on any phone is to tick Keep the screen on and put the phone face down. If waking on time really matters, set your phone's own alarm as a backup.
If you can't nap
NSDR keeps you awake, so it is unlikely to leave you groggy the way waking from deep sleep can. In a 2026 trial of 60 active young adults, a 25-minute nap raised readiness to perform where 10 minutes of NSDR had no significant effect.
So if you can nap, the nap is the better bet. If you can't lie down or drop off, the session under the timer is a guided rest you stay awake for.
Questions
How long should a nap be?+
10 to 20 minutes of sleep is the usual advice. In a 2006 study, a 10-minute nap helped as soon as people woke, and some of the benefits lasted up to 155 minutes. The benefits of a 20-minute nap took 35 minutes to show, and a 30-minute nap brought grogginess first. Our napping guide has more on timing.
Will it wake me if my phone is locked?+
Usually, yes. The bell is part of an audio file that starts playing when you press Start, and phones keep playing a page's audio with the screen locked. It stops if you close the tab or another app plays sound. Try it once, and set a phone alarm as well if waking on time matters.
Why add time to fall asleep?+
The nap lengths in the research are minutes asleep. Most people take a few minutes to drop off, so the timer adds them on. Choose None if you fall asleep straight away.
Can I set a 30-minute nap?+
Not as minutes asleep. The 30-minute nap in the 2006 study brought a spell of grogginess first, so the timer stops at 20 minutes of sleep. With 10 minutes to fall asleep added, the whole timer runs 30 minutes.
What does the wake-up sound like?+
A soft two-note bell, made in your browser. It starts quietly and gets louder for about a minute and a half, then keeps ringing for about 30 seconds. Press I'm awake to stop it.