This white noise generator plays real white noise, made in your browser: random sound with the same energy at every frequency from 20 Hz to 20 kHz. Use it to mask background noise while you sleep or work, set a sleep timer that fades it out slowly, or compare it with pink and brown noise using the color keys. The live display checks the spectrum as it plays, so you can see that the noise is what it says it is. It works on phones, tablets and computers with any speakers or headphones, and there is nothing to install.
How to use the white noise generator
- Turn your device volume down, then press Play white noise. It fades in over a second and a half.
- Raise the volume until the noise covers the sounds that bother you, and no further.
- Choose Stereo for a wide, airy sound with different noise in each ear, or Mono for the same noise in both.
- For sleep, pick a Sleep timer and a Fade out length. The noise fades away gently at the end instead of stopping dead.
- On a phone, turn on Keep playing with the screen off before you press Play.
- Try Pink and Brown. Most people find one of the three far more pleasant than the others.
White, pink and brown noise compared
| Color | How its energy is spread | Sounds like | Often used for |
|---|---|---|---|
| White | Equal energy per hertz, so each octave up holds twice as much | Hiss, a TV tuned to nothing, a fan | Masking speech, testing treble |
| Pink | Equal energy per octave, falling 3 dB per octave per hertz | Steady rain, wind in trees | Sleep, speaker calibration |
| Brown | Falling 6 dB per octave per hertz | A low roar, heavy surf, a plane cabin | Sleep, focus, covering low rumble |
The bars in the tool group the sound into thirds of an octave, the way an audio analyzer does. That is why white noise climbs to the right on the display: there are far more hertz in the upper octaves, and each one carries the same energy. The yellow line is what perfect white noise should show; the bars settle onto it within a few seconds.
What the readouts mean
| Readout | What it tells you | Normal value |
|---|---|---|
| Color | Which noise is playing and its spectrum | White, flat spectrum |
| Slope | Change in energy per hertz for each octave | 0 dB for white noise |
| Level | The RMS level sent to your system, before its volume control | −28 dBFS at 50% volume |
| Timer | Time left before the fade starts and ends | Off, or counting down |
| Channels | Stereo or mono | Stereo |
White noise for sleep: what the research says
The evidence is thin, and most of the studies behind it are small.
- In 1990, Spencer and colleagues found that 16 of 20 newborns fell asleep within five minutes with white noise, against 5 of 20 without it (Archives of Disease in Childhood).
- In a sleep lab study of four healthy volunteers, Stanchina and colleagues found that adding white noise to recorded intensive care unit noise cut the brief arousals from sleep that the unit noise caused. They suggested it works by narrowing the gap between the background and the loud peaks (Sleep Medicine, 2005).
- A 2021 systematic review by Riedy, Smith, Rocha and Basner in Sleep Medicine Reviews found the overall evidence that continuous noise improves sleep to be of very low quality.
Volume matters more than color. When Hugh and colleagues tested 14 infant sleep machines at full volume, all of them went above 50 dBA at 30 cm, the limit recommended for hospital nurseries, and three went above 85 dBA (Pediatrics, 2014). Keep any noise you sleep with quiet, and check the level at your pillow with a decibel meter.
White noise for focus and masking
White noise is good at covering speech, because it has plenty of energy in the 1 to 4 kHz range where consonants live. That makes it useful in open offices and shared rooms. For attention, results vary: Söderlund and colleagues found that white noise raised memory task scores in children with ADHD but lowered them in children without ADHD (Journal of Child Psychology and Psychiatry, 2007). If it distracts you, try pink noise, which is softer in the treble.
The noise sounds harsh, hissy or uneven
- That is white noise. Its energy is heaviest in the top octave. If it feels harsh, switch to Pink or Brown before changing anything else; the brown noise page explains the deepest of the three.
- Sound enhancements are on. Equalizers, bass boost and "spatial" effects colour the noise. On Windows, open Settings, then System, then Sound, pick your speakers and turn Audio enhancements off.
- It crackles at higher volume. Small speakers distort with loud noise. Lower the volume or use headphones.
- It swirls or warbles on Bluetooth. Noise is the hardest sound for wireless audio to compress, so cheaper Bluetooth links can make it shimmer. A wired connection sounds clean.
It stops when the phone screen turns off
Phones pause web pages to save battery. Turn on Keep playing with the screen off: the noise then plays through your browser's media player, with controls on the lock screen. On iPhone and iPad use the side buttons for volume in this mode, and set the Clock app timer to Stop Playing if you want a guaranteed stop. On Android, battery saver can still stop the browser; keep the page open in front. A laptop must not go to sleep, so check its power settings.
Using white noise to test speakers
Because white noise is bright, it shows treble faults fast. Play it through each speaker in turn with Mono and the system balance: a speaker that sounds duller than the others has a weak or damaged tweeter. To check each channel on its own, run the speaker test. To check the level of each speaker, pink noise at the calibration level is the better signal, and the tone generator finds rattles at single frequencies. If you want to run in new headphones with hours of noise, the headphone burn in tool mixes noise, sweeps and rests on a timer.
What a white noise generator cannot measure
The tester controls the digital level exactly, but not how loud the noise is in your room, which depends on your volume, speakers and distance. Use a sound level meter for that. Each color is made as a loop of about 22 to 24 seconds with an exact spectrum and no click where it repeats; you will not hear the repeat, but it is there. Nothing here is a medical treatment, and noise cannot cure insomnia or tinnitus.
White noise questions
Is white noise good for sleep?
It helps some people, mostly in noisy places, because a steady sound hides sudden ones like traffic or a door. The research is thin: a 2021 review in Sleep Medicine Reviews by Riedy and colleagues rated the evidence for noise as a sleep aid as very low quality. If it helps you, keep it quiet.
Is it safe to sleep with white noise on all night?
Keep it quiet and away from your head. Aim for no louder than a quiet conversation where you lie, and put the speaker across the room rather than by the pillow. For a baby, keep a machine well away from the cot and on a low setting, because many go far louder than nursery guidelines allow.
What is the difference between white, pink and brown noise?
All three are random, but they spread their energy differently. White noise has the same energy at every frequency and sounds hissy. Pink noise has the same energy in every octave and sounds like steady rain. Brown noise falls off faster still and sounds like a low roar. Switch between them with the Color keys.
Does this white noise keep playing when my screen turns off?
On a computer, yes, as long as the computer does not sleep. On a phone, turn on Keep playing with the screen off. It hands the noise to your browser's media player, which most phones keep playing when the screen locks.
Can I download the white noise?
Yes. Download a loop as WAV saves about 22 seconds of white noise at your volume setting. The file is made so its end joins its start without a click, so set your music player to repeat it.
Why does white noise sound like hiss?
Because each octave up holds twice as many frequencies as the one below, and white noise gives each frequency the same energy. Half of all its energy sits in the top octave, roughly 10 to 20 kHz, which we hear as hiss. Pink and brown noise move that energy down.