Discover your perfect sleep rhythm with our comprehensive suite of free sleep analysis tools. Wake up refreshed and energized.
Sleep is not just about duration—it's about timing. Your body follows natural sleep cycles that typically last 90 minutes, moving through different stages of light sleep, deep sleep, and REM sleep.
Waking up during the wrong phase of your sleep cycle can leave you feeling groggy and tired, even after a full night's rest. By understanding and aligning with your natural sleep patterns, you can wake up feeling refreshed and energized.
Slumber Sync provides you with the tools you need to calculate optimal sleep and wake times, analyze your sleep patterns, and improve your overall sleep quality—all for free.
Calculate your optimal sleep and wake times
Track and analyze your sleep patterns
All tools available completely free
Choose from our comprehensive suite of sleep analysis tools
Calculate optimal wake times based on your bedtime
Find the best bedtime for your desired wake time
Determine optimal wake times from your sleep time
Track and calculate your accumulated sleep debt
Calculate optimal nap durations and timing
Assess and improve your sleep quality
Understand your natural circadian rhythm
Analyze your sleep stages and patterns
Our calculations are based on sleep science research and circadian rhythm studies
All calculations are performed locally in your browser—your data never leaves your device
Access all our sleep tools and calculators without any cost or registration