What is the difference between white, pink and brown noise?
White noise has equal energy at every frequency (bright, hissy). Pink noise lowers high frequencies by 3 dB per octave, sounding softer and more balanced — many people find it gentler for sleep. Brown (red) noise reduces high frequencies more aggressively, sounding deeper and rumblier, like a strong ocean or waterfall.
Are the sounds synthesized or recorded?
All sounds in this mixer are generated in real time by the Web Audio API in your browser using filtered noise, oscillators and envelopes. No audio files are downloaded and no upload is needed, so the page works offline once loaded.
How does the sleep timer work?
Pick a duration and the mixer will gradually fade all layers to silence over the last 5 seconds, then stop playback. The page itself stays open so you can restart whenever you want.
Can I save my mix?
Yes. Three built-in presets (Sleep, Focus, Relax) recall volume levels for every layer. Your current mix is auto-saved in your browser between sessions on the same device.