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CortexLit tool · Sleep · Runs offline · No account

Morning Grogginess Checker

Work out how long your groggy window is likely to be, and what would fit in it instead of a decision you will regret.

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This tool gives general information based on the research summarised in The Snooze Button: What the Studies Found About Morning Grogginess. It is not a medical device, does not diagnose, and does not replace advice from your clinician.

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Free (this page)
  • groggy-window calculation
  • task-placement suggestion
  • safety warning for driving
  • text export and print
  • all citations and cautions


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  • calendar (.ics) export of the window
  • unlimited share images
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Free tier: 1 share image per result.






Commercial disclosure: optional paid Plus tier; all evidence, cautions and the main result are free. No affiliate links, no sponsors.







What this is based on


Every output names at least one verified PubMed source. Identifiers were verified on 2026-10-11 in an earlier batch and carried over into this build; they were not re-queried here, and no retraction database was checked. Verification was at abstract level.


Ogawa 2022
Ogawa K, Kaizuma-Ueyama E, Hayashi M. Effects of using a snooze alarm on sleep inertia after morning awakening. J Physiol Anthropol. 2022;41(1):43. doi:10.1186/s40101-022-00317-w. PMID: 36587230.
PMID 36587230 · controlled experiment · weight 0.5 · abstract level
Hilditch 2017
Hilditch CJ, Dorrian J, Banks S. A review of short naps and sleep inertia: do naps of 30 min or less really avoid sleep inertia and slow-wave sleep?. Sleep Med. 2017;32:176-190. doi:10.1016/j.sleep.2016.12.016. PMID: 28366332.
PMID 28366332 · narrative review · weight 0.2 · abstract level
Sundelin 2024
Sundelin T, Landry S, Axelsson J. Is snoozing losing? Why intermittent morning alarms are used and how they affect sleep, cognition, cortisol, and mood. J Sleep Res. 2024;33(3):e14054. doi:10.1111/jsr.14054. PMID: 37849039.
PMID 37849039 · controlled experiment · weight 0.5 · abstract level


Limits: Grogginess length is self-reported. Lab studies measured sleep inertia shortly after waking and found conflicting effects of snoozing, so this tool plans around your own window rather than predicting it.







Privacy


Inputs stay in this page's memory. There is no telemetry, no analytics call and no network request. Saving is opt-in, local to this browser, deletable, and unencrypted.