Privacy
SleepCycleHub has no accounts, no logins and no database of visitors. Here's exactly what happens to your data.
Calculations stay on your device
Every calculator runs in your browser. The times, ages and drinks you enter are not sent to our server.
What we remember in your browser
To save you retyping, some tools store your last inputs in your browser's localStorage: the cycle calculator (wake and bed times, fall-asleep minutes, cycle length), caffeine log, sleep debt week, chronotype answers and your 12/24-hour clock choice. This data never leaves your device and you can delete it here:
The AI sleep planner
If you use the AI sleep planner, the text you type is sent through Vercel AI Gateway to an AI model to write your plan. We don't store it or attach it to any identity. Please don't include names or sensitive medical details. Your IP address is held briefly in memory to limit how many plans can be requested per hour.
Analytics
We use Ahrefs Web Analytics, a cookieless, privacy-friendly analytics tool, to count page views and see which tools are useful. It doesn't use cookies or build advertising profiles.
Hosting
The site is hosted on Vercel, which processes standard server logs (such as IP address and user agent) to deliver pages and prevent abuse.
Not medical advice
SleepCycleHub provides general educational information about sleep timing. It isn't a substitute for professional medical advice, diagnosis or treatment.
Last updated 27 September 2026.