Sleep notes

Is Hitting Snooze Bad for You? What the Research Says

By ToSleep AI · 2026-09-22

Research reviewed September 22, 2026. Published by the developer of ToSleep AI; not independently clinically reviewed. The cited researchers and institutions are not affiliated with ToSleep and do not endorse it.

The short answer: Research does not show that pressing snooze is universally harmful—or universally helpful. One small laboratory study found more prolonged sleep inertia after repeated alarms. Another small crossover study in habitual snoozers found that a 30-minute snooze period improved or did not change several cognitive results immediately after rising, while costing about six minutes of sleep. The studies tested different people and alarm patterns, so neither result settles what your snooze button does over months or years.

What counts as snoozing?

Snoozing means waking to an alarm, intending to return to sleep, and using another alarm to wake again later. That can be one delayed alarm or a series of alarms.

It is not the same as setting one alarm for a later time. It is also not the same as a smart wake window that chooses one start time before a final deadline. The key feature is repeatedly interrupting the last part of sleep.

Snoozing is common, but prevalence depends on who and how researchers measure. A 2022 study of 450 full-time workers found that 57% identified as snoozers. Mattingly et al., 2022

A much larger 2025 observational study analyzed more than three million logged nights from users of one sleep-monitoring phone app. Among logged sessions, 55.6% ended with a snooze alarm. When snooze was used, the mean was 2.4 presses and 10.8 minutes. That describes app use; it does not prove effects on health or represent every sleeper. Two authors were employed by the app company, which readers should know when interpreting the dataset. Robbins et al., 2025

Why do people hit snooze?

The answer may be more informative than the button itself.

In a 2024 survey of 1,732 respondents, snoozing was more common among younger people and later chronotypes. Snoozers also reported more morning drowsiness and slightly shorter sleep on workdays. These associations do not establish cause: snoozing may be a response to difficult mornings rather than the reason those mornings are difficult. Sundelin et al., 2024

Another survey of 293 Japanese university students found that concern about not waking on time and wanting reassurance before sleep were prominent reasons for using snooze. That suggests a second function: repeated alarms can feel like insurance against oversleeping. Ogawa et al., 2022

What happens to sleep during the snooze period?

Repeated alarms fragment the final minutes of sleep. The unresolved question is whether that tradeoff helps the transition to waking or simply interrupts sleep you needed.

In the 2024 laboratory study, 31 habitual snoozers completed two conditions. On one morning they slept until their normal final alarm. On another, the first alarm sounded 30 minutes earlier and they snoozed three times at intervals of nine to ten minutes. Polysomnography showed that they slept for a median of about 23 of those final 30 minutes in the snooze condition—about six minutes less than when they slept through.

The snooze period contained more brief awakenings and lighter N1 sleep. No participant entered N3 deep sleep during those final 30 minutes with snoozing, whereas 10 of 31 had at least some N3 in the sleep-through condition. Whole-night sleep-architecture differences were small and not statistically significant in this single-night comparison. Sundelin et al., 2024

Those findings cannot be turned into “snoozing moves everyone into the perfect stage.” The experiment involved habitual snoozers, one 30-minute pattern, a sleep laboratory and a small sample. Longer snoozing, non-habitual snoozers and repeated use over many mornings could behave differently.

Does snoozing make sleep inertia better or worse?

The honest answer is that the small experimental studies conflict.

One study found a possible short-term benefit

In the 2024 crossover experiment, habitual snoozers performed better or no worse on four cognitive tasks immediately after final waking following the snooze condition. The clearest benefits were limited, and the authors noted that the strength of statistical evidence varied by outcome. Snoozing did not clearly change subjective sleepiness, mood or the cortisol awakening response. By 40 minutes after rising, much of the immediate difference had narrowed. Sundelin et al., 2024

Another study found more prolonged grogginess

A 2022 laboratory experiment used 10 habitual snoozers. Their alarms repeated at five-minute intervals during the final 20 minutes. Snoozing reduced sleep by about four minutes during that period, increased wake and N1 time, and produced results the authors interpreted as prolonged sleep inertia compared with a single alarm. Ogawa et al., 2022

Ten participants are not enough to estimate an effect for the general population. But the finding matters because it prevents an equally simplistic claim that snoozing is beneficial.

Why can both results exist?

The studies differed in interval length, total snooze time, outcome tests and sample. Both enrolled young habitual snoozers and tested only one or a few laboratory mornings. Small changes in protocol may matter, and chance is harder to rule out in small samples.

They also measured sleep inertia: the temporary drop in alertness and performance after waking. Sleep inertia already varies with prior sleep loss, biological timing, task and individual. Read our guide to why you can wake up tired after enough sleep.

Is snoozing bad for your long-term health?

Current studies do not establish that answer.

The 2022 worker study combined surveys with more than 100,000 wearable-recorded nights. Snoozers showed some differences in heart rate and wearable-estimated sleep before waking, but this was observational. People who snooze differed from people who did not, and the consumer wearable’s stage estimates were not polysomnography. The authors explicitly called for validation and more research before interpreting health effects. Mattingly et al., 2022

The 2025 app study was also observational and concluded that future research is needed to determine effects on daytime performance. A large dataset can measure behavior precisely while still being unable to show whether the behavior caused a health outcome.

So “snooze damages your heart” and “snooze is good for your brain” both go beyond the evidence.

Should you stop using the snooze button?

Use the reason and pattern to decide, not a universal rule.

If snooze replaces sleep: Setting an alarm 30 minutes early just to spend those 30 minutes in fragmented sleep may be less useful than protecting a realistic sleep opportunity and waking once.
If you sleep through alarms: Repeated alarms may be masking sleep restriction, an incompatible schedule or another sleep problem. Record when it happens rather than only adding louder alarms.
If one brief snooze helps: The 2024 study provides limited evidence that a structured 30-minute period did not impair—and sometimes improved—immediate cognition in habitual snoozers. It does not prove the same for every interval or person.
If mornings affect safety: Allow time after waking before driving or doing safety-critical work. A snooze button is not proof that sleep inertia has passed.
If difficulty waking is persistent or severe: Excessive daytime sleepiness, loud snoring, gasping, breathing pauses or repeated inability to wake deserves discussion with a qualified clinician, regardless of an app score.

How ToSleep differs from a snooze alarm

ToSleep’s current Apple Watch flow does not schedule repeated snooze alarms.

Instead, you choose a latest wake time and an earlier wake window. Within that window, ToSleep can use two consecutive, recent wrist-based estimates to choose when one gradual wake session begins. If the estimates are missing or not confident enough, it waits and still starts by the final deadline.

The wake session begins with gentle haptics and later adds gradually increasing sound if you do not stop it. Pressing “I’m up” or Stop ends the session; the current flow does not ask you to fall back asleep for another alarm.

That design avoids intentionally fragmenting sleep with a sequence of snooze alarms, but it is not clinical evidence that ToSleep reduces sleep inertia. Wrist stages are estimates from movement and available heart-rate signals, not brain-wave measurements. See how ToSleep works and what a sleep tracker can actually tell you.

A useful seven-morning test

If snoozing is part of your routine, collect a small personal baseline for seven mornings:

Record bedtime, final wake time and estimated sleep duration.
Record the number of alarms and minutes from the first alarm to getting up.
Rate morning alertness at rising and again 30 minutes later.
Note whether the previous night was unusually short, late or interrupted.
Compare patterns; do not declare a winner from one morning.

This will not diagnose a sleep disorder, but it can reveal whether snoozing is a deliberate transition or simply compensation for too little or poorly timed sleep.

Frequently asked questions

Is one snooze alarm bad for you?

There is no strong evidence that one brief snooze is inherently harmful for every adult. Effects likely depend on timing, duration, sleep need and the person. Long-term causal evidence is lacking.

Is it better to snooze or set a later alarm?

If both options leave the same final wake time, setting the later alarm preserves uninterrupted sleep. But a small study of habitual snoozers found possible immediate cognitive benefits from a structured 30-minute snooze period. The research does not identify one universal best choice.

Does snoozing cause more deep sleep?

Not in the 2024 laboratory study. Snoozing increased brief awakenings and light N1 sleep during the final 30 minutes and eliminated N3 during that interval. That result should not be generalized beyond the tested protocol.

Why do I feel worse after snoozing?

Repeated forced awakenings may extend the transition out of sleep, as one small study suggested. You may also be waking during your biological night or carrying sleep debt. A wearable cannot distinguish all of these explanations from one morning.

Is a smart wake window the same as snoozing?

No. A wake window lets an alarm choose one start time before a deadline. Snoozing uses repeated alarms after the first awakening and invites a return to sleep between them.

Sources

Wellness information, not medical advice.