Music / 03
White Noise Generator
Play white, pink, or brown noise in your browser for sleep, focus, or a crying baby, with a volume control and a sleep timer that fades out.
White Noise Generator: The noise is generated in your browser, not streamed: white noise has equal power at every frequency, pink noise falls by 3 dB an octave so it sounds softer, and brown noise falls by 6 dB an octave, a deep rumble. Each channel is generated separately for a wide stereo sound, and a timer fades the sound out over its last 30 seconds. Runs 100% locally in your browser with zero server file uploads.
- Category
- Everyday tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
The sound is made in your browser and keeps playing with the screen off, as long as the tab stays open. With a timer it fades out over the last 30 seconds. Keep the volume moderate, especially for babies and for long listening.
The colours of noise
Noise is named after light: white noise has equal power at every frequency, like white light containing every colour, and sounds like static or a fan on high. Pink noise loses 3 dB of power with each octave, so every octave carries the same energy; to the ear it is softer, like rain. Brown noise, named after Brownian motion rather than the colour, loses 6 dB an octave and is mostly low rumble.
All three are generated here from random numbers and filtered to their slopes, which were measured: the page's pink noise falls by 3 dB an octave and its brown noise by 6 dB, to within half a decibel.
Using it for sleep and focus
Steady noise works by masking: a sudden sound such as a door or traffic stands out less against a constant background. A moderate level is enough; louder is not more effective, and for babies the evidence points to keeping it quiet and at a distance. The timer fades the sound out over 30 seconds so the ending does not wake anyone.
For focused work in timed blocks, pair it with the Pomodoro timer; for a simple countdown, the online timer.
How to use it
- Choose white, pink, or brown noise.
- Set the volume and, if you like, a timer to stop after 15 minutes to 2 hours.
- Press Play; the sound keeps going with the screen off while the tab is open.
Privacy & limitations
Nothing is downloaded or sent; the sound is made on your device. Your choices are remembered in this browser.
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Frequently asked questions
What is the difference between white, pink, and brown noise?
White noise has the same energy at every frequency, which sounds bright and hissing. Pink noise has less energy at high frequencies, like steady rain, and many people find it more pleasant. Brown noise drops off faster still, a low rumble like a waterfall or the inside of a plane.
Is white noise safe for babies?
A 2014 study in the journal Pediatrics measured 14 infant sleep machines and found that at full volume, close to the cot, all were louder than the 50 dB recommended for hospital nurseries, and three were loud enough to risk hearing damage over a night. Keep the volume low, put the phone or speaker well away from the cot, and use the timer rather than playing all night.
Will it keep playing with the screen off?
Yes, while the browser tab stays open. On phones, some battery savers stop background audio after a while; plugging in or keeping the tab in front avoids that.
Does it use data?
No. The sound is calculated on your device, so it works offline once the page has loaded and uses no data while playing.
Free tool · runs in your browser · no account required