Clear by design
About & privacy.
HeavySleeper is a free browser tool for creating a wake-up routine with several cues.
What this version does
Set a local wake-up time, choose one of fifteen alarm sounds and optionally add gradual screen light and vibration. Choose three sums, a room-code task or no task. You can add a follow-up check after two or five minutes. A normal sound alarm rises over the time you choose (30 seconds to 5 minutes) to the level you select, subject to your device volume.
The first alarm expires after 10 minutes without a response. Completing the task starts the optional follow-up timer; its alarm expires after five minutes without confirmation. The demo reaches alarm time after 10 seconds and uses a 10-second follow-up wait. The unanswered demo alarm expires after three minutes, and its follow-up after two minutes.
Browser limits
The page must stay visible and the screen unlocked. Hiding the page cancels the session. Closing or reloading also cancels it. The app cannot unlock a phone, change its hardware brightness or guarantee an alarm in the background. Keep-awake can be unavailable, denied or released by the device. Use a regular phone alarm as backup.
Web vibration is supported in some Android browsers, including Chrome, on suitable hardware. iPhone Safari does not implement the web vibration API. A successful request does not guarantee that a motor vibrated. Test on the actual device. Tasks do not detect whether you are fully awake or verify your location. You can always stop the session.
Technical references: W3C vibration support, MDN vibration behaviour, MDN Screen Wake Lock and MDN audio playback policies.
A routine tool, not a medical service
We do not diagnose sleep disorders, measure sleep quality or claim that this tool will treat sleep problems or reliably wake every user. The guide provides general information and links to healthcare sources. Seek professional advice for persistent sleep problems or daytime sleepiness that affects your life.
Sound credits
Red Alert, Siren, Klaxon, Fire Bell, Buzzer, Classic Beeper, Morning Beeps, Wind Chimes, Music Box, Birdsong, Ocean Waves and Soft Music are generated live in your browser by this site’s own code with the Web Audio API. They are not recordings and contain no third-party samples. Construction Site uses “Noisy Construction Site” by Nqire and Heavy Traffic uses “Traffic, horns, engines, reverse beeps, truck, NYC” by TRP. Both recordings are public domain (CC0) on Freesound, shortened here to 30-second loops. If you choose your own audio file, it plays only on your device and is never uploaded. Visit WakeUpSounds.com for personal alarm and ringtone downloads.
Privacy
This version has no accounts, advertising trackers or cookies. Visits are counted anonymously with Cloudflare Web Analytics, which sets no cookies. Your browser keeps a copy of the site files, and of any alarm sound after you first play it, so the page also works offline; if you close the install hint, that choice is remembered on your device. You can clear both in your browser settings. Your settings, answers and room code stay in the current page and are not submitted to a server. Reloading or closing the page clears them. Saving a code card downloads an SVG file to your device; you can delete it there whenever you wish.
All fonts are system fonts. Audio is downloaded from this website when requested. Cloudflare processes technical request data to deliver and protect the website; see Cloudflare’s privacy policy. If you email us, we receive your email address and message to respond to your enquiry. External links take you to sites with their own privacy practices.
Operator and contact
HeavySleeper.app is a project by Takreparation Skåne AB, Sweden.
Organisation number: 556988-5931.
Email: info@heavysleeper.app.
First version · 15 September 2026