Steady noise for sleeping, with a screen that stays perfectly dark. Press play and choose your texture: classic white noise (bright, like a fan), pink noise (softer, like steady rain), green noise (fuller, like ocean surf) or brown noise (deep, like a distant waterfall). The audio is generated live in your browser — it never loops, never buffers and never shows an ad at 3 a.m.
On OLED phones the black screen means the display is effectively off while the sound plays. A sleep timer can fade the noise out after 15 minutes to 8 hours.
Brown noise vs white noise vs pink noise
All three are "colored" noise, and the names borrow an analogy from light: white noise holds every frequency at equal strength, the way white light holds every color. The color simply describes how the energy is spread across the spectrum — and that distribution is the only real difference between them.
White noise — the bright one
Equal power at every frequency, which puts a lot of energy up in the treble. It sounds like a hissing fan, an untuned radio, or television static. Because its energy sits where human hearing is most sensitive, it covers higher-pitched sounds — voices, keyboard clatter, a TV through the wall — better than the others. It is also the one people most often call harsh after an hour.
Pink noise — the balanced one
Power drops by 3 dB per octave, so there is equal energy in every octave rather than at every individual frequency. That is much closer to how sound behaves in nature, which is why pink noise gets described as steady rain, wind through trees, or a waterfall heard from a distance. Most people find it easier to listen to for hours than white noise.
Brown noise — the deep one
Power drops twice as fast, 6 dB per octave, leaving a deep rumble with almost no hiss — heavy surf, a jet cabin, thunder rolling somewhere far away. It is named after Robert Brown and the random walk of Brownian motion rather than the color, and you will also see it called red noise. It became the internet favourite for sleep and focus around 2022, and the appeal is simple: nothing in it is sharp.
Green noise — the nature one
Green noise is white noise with its energy pushed toward the middle of the spectrum, around 500 Hz. That mid-band emphasis is roughly where the broadband sounds of nature sit, which is why green noise is described as ocean surf, a steady waterfall or a rushing stream. It is fuller than pink but without the deep rumble of brown, and it has become a popular pick for sleep for exactly that reason — it sounds less like a machine and more like being outdoors.
Which one should you actually use?
Match the noise to whatever you are trying to cover, because masking works best when the masking sound occupies the same frequency range as the sound you want gone. Low rumbling problems — traffic, a neighbour's bass, an aircraft cabin — disappear most efficiently under brown noise. Higher-pitched problems — conversation, a television, hallway noise — are handled better by white or pink. Green sits in between and tends to feel the most natural for a full night. If you have no specific enemy and simply want something to sleep to, start with green or brown at a low volume and move toward pink or white if you need to cover sharper sounds.
On the research: the evidence is thinner than the internet suggests. A few small studies have reported that pink noise may deepen slow-wave sleep, and steady sound plainly helps some people drift off by smoothing over sudden noises — but the overall body of evidence is limited and mixed. Treat all three as comfort tools rather than treatment, keep the volume moderate, and if sleep trouble persists it is worth raising with a doctor.
What people use it for
Sleep & travel
Mask hotel corridors, street noise and snoring with a steady noise floor. Brown noise at low volume is the crowd favorite for sleep.
Baby soothing
Constant, unchanging noise (at a safe distance and moderate volume) helps many infants settle — and this one never ends mid-nap like a looped video.
Focus masking
White or pink noise in headphones flattens open-office chatter into an ignorable hum.
Frequently asked questions
What is the difference between white, pink and brown noise?
They differ in how energy spreads across frequencies: white is equal at all frequencies (hissy), pink rolls off highs (rain-like), brown rolls off harder (deep rumble). Softer spectra are usually more comfortable for all-night listening.
Will it keep playing with the screen locked?
On desktop, yes, as long as the tab is open. On mobile, keep the browser in the foreground with the black screen on — on OLED phones this uses almost no display power.
Does the noise loop?
No — it is synthesized continuously in real time, so there is no loop seam and nothing to download.
Is brown noise better than white noise for sleep?
Neither is universally better; they cover different problems. Brown noise has far less treble, so most people find it gentler over a whole night and it masks low rumbles like traffic more efficiently. White noise reaches higher frequencies and hides voices and other sharp sounds better. If you are unsure, try brown first — it is the one people rarely describe as harsh.
Why does brown noise sound so much deeper?
Its energy falls by 6 dB per octave as frequency rises, twice as steeply as pink noise, so almost everything above the low mids is rolled away. What is left is the rumble, which is why it gets compared to surf or a distant engine.
What is green noise?
Green noise is white noise concentrated around the middle of the spectrum, near 500 Hz — roughly where the broadband sounds of nature sit. That is why it is often compared to ocean waves, a waterfall or a steady stream, and why many people find it the most natural of the colors to sleep to.
Is it safe to run noise all night?
Keep it at a moderate volume — roughly the level of a quiet shower, and quieter still for infants or when using headphones. Loud sound over many hours is the part worth avoiding; the noise itself is ordinary audio.