Up to five layers
Stack noises, tones and recordings. Each layer has its own fader, and you can mute one without losing its level.
Free iPhone app · no account · no ads
Your own mix of calm sound.
Layer brown noise, gentle rain and a soft tone, set each one with its own fader, then let a timer fade it all out while you drift off.
iPhone, iOS 15 or later. Every feature is free.
Paused · 5 layers ∞
70
Brown noise
36
Rain on a metal roof
79
Stream
29
Lake shore
15
Sine 528 Hz
One deck, five layers, all yours
Everything happens on a single screen that works like a small mixing desk.
Tone generator, 20–1000 Hz
Sine or triangle wave, tuned with a dial or by typing a number. Quick picks include 432 and 528 Hz.
15 nature recordings
Rain on a roof, a window or a lake, wind in the trees, ocean, stream, waterfall, fire, fan, train and a singing bowl, all cut into seamless loops.
Listen before you add
Every sound in the library has a play button, so you hear it at the right level before it goes on your deck.
Timer with a gentle fade
15, 30, 45 or 60 minutes, 8 hours, any length up to 12 hours, or no timer. The last 30 seconds fade out so the stop does not wake you.
Saved mixes
Save the mixes you like and switch between them in a tap. The app reopens your last deck, paused, exactly as you left it.
Plays with the screen off
Keeps playing in the background and on the lock screen, with controls there too. You can also let it play alongside other apps' audio.
Private and offline
No account, no ads, no tracking. Every sound is generated or stored on your iPhone, so it works with no connection at all.
The sound library
Generated sounds never repeat. Recordings are real places, looped without a seam.
Generated
- White noise
- Pink noise
- Brown noise
- Tone generator
Tone presets (Hz): 174 285 396 417 432 528 639 741 852 963
Recorded
- Steady rain
- Rain on a metal roof
- Rain on a window
- Rain in the forest
- Rain on water
- Wind
- Wind in the trees
- Ocean
- Lake shore
- Stream
- Waterfall
- Fire
- Fan
- Train
- Singing bowl
All recordings are public-domain (CC0) field recordings from Freesound. Credits →
How it works
-
Add your sounds
Open the library, play a few to hear them, and add up to five.
-
Balance the faders
Drag each fader until the mix feels right. Mute a layer to try the mix without it.
-
Set a timer and rest
Pick a duration, press Play and put the phone down. The sound fades out and stops by itself.
Questions
Is Sleep Static really free?
Yes. Every feature is free, with no subscription and no ads. There is one optional “Buy me a coffee” tip in Settings; it unlocks nothing.
Does it keep playing when the screen is off?
Yes. It plays in the background and on the lock screen, and you can pause or resume from there. With a timer, it fades out and stops on its own.
Can I listen to a podcast or music at the same time?
Turn on “Mix with other audio” in the timer sheet. Sleep Static then plays alongside other apps instead of pausing them.
Do I need an internet connection?
No. All sounds are generated or stored on the iPhone. The app does not need a network for anything except the optional tip.
Do 432 Hz or 528 Hz tones heal or improve sleep?
Many people like these tones for relaxing, so they are one tap away. Sleep Static makes no medical or health claims about any sound or frequency.
Which languages does the app speak?
Fifteen: English, Tiếng Việt, 简体中文, 繁體中文, Español, Português (Brasil), Français, Deutsch, Русский, Türkçe, Bahasa Indonesia, हिन्दी, العربية, 日本語, 한국어. You can change the language inside the app at any time.
Nothing leaves your iPhone
No account, no analytics, no ads. Your mixes and settings are stored only on your device.