How to use the pink noise generator
- Press Play (or the Space bar). The pink noise fades in smoothly.
- Adjust the Volume until the sounds you want to block blend into the background, and no higher.
- Pick a Sleep timer, from 15 minutes to 8 hours. The sound fades out over the final 45 seconds instead of stopping abruptly.
- Use Softness to make the sound darker. At the left end you hear the full pink spectrum; to the right the highest frequencies are gently rolled off.
- Turn on Gentle variation for a slow, barely noticeable drift in tone and level, which some people find more natural than a perfectly fixed sound.
Settings are remembered in this browser. On a phone, lock the screen and leave the tab open: on most phones the noise keeps playing and appears in the lock-screen media controls.
What is pink noise?
Pink noise is random noise whose power spectral density is proportional to 1/f: every time the frequency doubles, the power per hertz halves, a fall of about 3 dB per octave. Because each octave is twice as wide as the one below it, those two effects cancel out, and every octave carries the same energy. The octave from 100 to 200 Hz has as much power as the octave from 5,000 to 10,000 Hz.
That matters because we hear pitch in octaves. White noise, with equal energy per hertz, sounds top-heavy and hissy; pink noise sounds balanced, closer to steady rain, wind in trees or a distant waterfall. It is also called 1/f noise or flicker noise, and the same 1/f pattern turns up in electronics, heartbeat intervals and many natural signals.
Audio engineers use pink noise to test speakers and tune rooms, because on an octave-band analyser it shows up as a flat line. This generator makes it in your browser by passing random samples through a well-known filter (Paul Kellet's refined method) that follows the 1/f slope to within a fraction of a decibel across the audible range. Two long buffers with different loop lengths play together, so the sound never repeats audibly, and the left and right channels are independent.
Pink noise vs white noise
| White noise | Pink noise | |
|---|---|---|
| Spectrum | Flat: equal power per hertz | 1/f: equal power per octave |
| Slope | 0 dB per octave (per hertz) | −3 dB per octave (per hertz) |
| Sounds like | Static, a hair dryer, hissing air | Steady rain, wind, rustling leaves |
| Often chosen for | Masking voices and sharp sounds | Long listening and sleep when white noise feels harsh |
Pink sits between white noise and the deeper brown noise, which falls twice as steeply (6 dB per octave). If pink is still too bright, try brown; if you want something even more mellow and mid-focused, try green noise. The guide white, pink and brown noise: what's the difference? compares all the colours.
When people use pink noise
- Sleep: to cover traffic, neighbours or a partner's snoring, especially by people who find white noise too sharp.
- Focus and reading: a soft, even backdrop for studying or working in a noisy space.
- Relaxation: its rain-like quality is calming for many people. If you prefer real texture, the rain sounds page adds drops and optional thunder.
- Audio testing: setting speaker levels and checking the frequency balance of a room.
Does pink noise improve sleep or memory?
Pink noise has attracted attention from sleep research. A few small laboratory studies played short bursts of pink noise timed to the slow brain waves of deep sleep and reported stronger slow-wave activity, and in some cases better recall of material learned the evening before. Those experiments used brain monitoring to time each burst precisely, and the samples were small. Playing continuous pink noise all night is a different thing, and there is no good evidence that it reproduces those effects.
For ordinary use, the most reliable benefit is the same as for any steady sound: masking. A constant background makes sudden noises less noticeable, which can make it easier to fall and stay asleep in a noisy environment. Reviews of noise as a sleep aid have rated the overall evidence as low quality, and results vary from person to person. Pink noise is a comfort tool, not a treatment for insomnia, ADHD or tinnitus; persistent sleep problems are worth discussing with a doctor.
Listening safely
Keep the level moderate: quieter than normal conversation is usually enough to mask background noise. If you listen through earphones or headphones, keep the volume low, take breaks during the day and avoid loud all-night listening; a speaker across the room is easier on your ears. The volume control here is capped, but your device volume adds to it. To check how your ears are doing, try the online hearing test.
Privacy: the pink noise is generated live on your device by your browser. No audio is downloaded or sent anywhere, and only your settings are saved, in this browser's local storage. More sounds, including a fan, ocean waves and a sleep sounds mixer, are on the sleep and relaxation sounds page.
Frequently asked questions
What does pink noise sound like?
A soft, even "shhh" with more body than white noise, often compared to steady rain, wind or a distant waterfall. It has less hiss because its power falls by 3 dB per octave.
Is pink noise better than white noise for sleep?
Neither has been clearly shown to be better. Many people find pink noise more pleasant over a whole night because it is less bright, while white noise can be better at covering voices. Try both at a low volume.
Does pink noise improve deep sleep?
Small laboratory studies using precisely timed bursts of pink noise reported more slow-wave activity, but that method needs brain monitoring. There is no good evidence that a continuous pink noise track does the same.
Will pink noise keep playing with my phone locked?
On most phones, yes, as long as the browser tab stays open. The sound plays through a media player and shows up in the lock-screen controls. Some battery-saving settings can still pause it.
Why is it called pink?
By analogy with light: shifting white light towards lower frequencies makes it look reddish or pink, and pink noise has more energy at low frequencies than white noise.
How loud should pink noise be for sleep?
Just loud enough that disturbing sounds blend in, and quieter than normal conversation. Keep it especially low with earphones, and use the sleep timer if you only need it while falling asleep.
Updated