What Sleepyland is
Sleepyland is a free browser sound machine. It synthesizes brown, pink, or white noise, procedural ocean waves, and an airplane-like rumble in the page. The generator uses no recorded or hosted audio files, product accounts, or server-side audio.
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What you can do
- Choose Sleep, Relax, or Focus. Each state is a distinct engine recipe with its own rhythm, spectrum, and movement.
- Use Gentle, Balanced, or Strong Energy. Energy scales movement depth and pace without changing volume.
- Open Tune for noise color, shared warmth, independent noise and wave levels, and wave pace.
- Run Endless, Countdown, or Focus Interval sessions.
- Watch the live post-mix spectrogram and spectrum curve, including an interactive tap-and-hold filtered-noise spectrum.
Settings stay in this browser. Selected mode and session kind can also appear as categorical fields in bounded anonymous production analytics. Read the privacy page for what can leave the device.
What Sleepyland is not
Sleepyland is not a medical device, diagnosis, or treatment. The names Sleep, Relax, and Focus describe intended listening contexts, not guaranteed outcomes. Sleepyland Research publishes sourced guides and states that the publication is educational, not medical advice. Support does not provide medical advice, hearing-safety certification, or crisis services.
It is also not a supplement calculator. A Hraness reading note on creatine and cognition records that the cognitive-enhancement case is weak: later trials and reviews point, at most, to a small uncertain mental benefit, and large effects in healthy adults are unlikely. Sleepyland does not recommend, dose, or track creatine or any other supplement. It generates sound in the browser.
Who publishes it
Hraness lists sleepy.land among its public projects. The hosted product is free to use without an account. Sleepyland is open source on GitHub under the MIT License, and research contributions are welcome. The license page records the exact reuse terms and third-party boundaries.
A silent product demo shows mode selection, Tune, playback, and the live spectrum. The interactive sound machine is the product itself.
A separate reading note discusses rest and attention as a condition for work, starting from Henrik and Johanna Karlsson’s essay on how new ideas are born. Another reading take on habit and rest starts from William James: a rest environment is not a habit until the first small act starts. A later reading take on rest as a place where anxiety can become curiosity starts from Armin Ronacher.