Brown noise is a deep, low-frequency random sound whose power falls by 6 dB with every octave, so it rumbles rather than hisses. People compare it to strong wind, a distant waterfall, or the roar inside an airplane cabin. Many listeners find it the most comfortable noise color for hours of continuous listening because there is little high-frequency content to fatigue the ear.
This page opens a free brown noise generator that runs in your browser. There are no ads, no accounts and no tracking, and the code is open source. The sound is synthesized in real time with the Web Audio API rather than played from a recording, so it never loops and never repeats. Press play, set a sleep timer if you want one, and adjust the color slider to taste.
Free, no ads, no signup. Runs entirely in your browser.
If white noise is the hiss of an untuned television, brown noise is the sound of a jet passing overhead heard from inside a house, or surf breaking on a beach a few hundred meters away. It is dominated by bass. There is almost no sharpness to it, and at moderate volume it can feel more like a pressure in the room than a sound. Some people describe it as the audio equivalent of a weighted blanket.
Because the highs are so subdued, brown noise blends into the background more readily than white or pink noise. It rarely draws attention to itself, which is exactly what most people want from a sound they intend to ignore for eight hours. On small laptop speakers it can seem to vanish almost entirely, since those speakers cannot reproduce the bass that makes up most of the sound; headphones or a speaker with some low end will show you what it really is.
Brown noise has a power spectral density proportional to 1/f². In practical terms, every time the frequency doubles the power drops by 6 dB, which is twice the slope of pink noise. Going from 100 Hz to 1600 Hz, four octaves, the power falls by 24 dB. That is why the sound is so heavily weighted toward the bottom of the audible range.
The name has nothing to do with the color brown. It comes from Robert Brown, the botanist who described Brownian motion, the random jitter of pollen grains in water. Brown noise is the sound of a signal doing a random walk: each sample is the previous sample plus a small random step. You will also see it called red noise or Brownian noise. The full derivation is on the physics page.
The generator starts with white noise, a stream of uncorrelated Gaussian random samples, and integrates it: each output sample is the running sum of the input. Pure integration would drift without limit, so a small leak pulls the sum back toward zero, which keeps the signal bounded while preserving the 1/f² slope across the audible band. This happens sample by sample inside an audio worklet in your browser.
Nothing is downloaded and nothing is looped. A recorded brown noise track has to loop at some point and the seam is often audible as a subtle click or a change in texture. Synthesized brown noise has no seam because there is no file. It is new random data for as long as you leave it running.
The most common use is sleep. Brown noise masks the sudden sounds that wake people, such as doors, traffic and neighbors, without adding the bright hiss that some find irritating. The second most common use is concentration. A steady low rumble covers speech in an open office or a shared apartment, and a large number of adults with ADHD say it helps them settle into work; see brown noise and ADHD for what the evidence does and does not show.
It is also used for masking low-frequency tinnitus, for calming anxious pets during fireworks and thunderstorms, and as a bed layer in ambient music and sound design where a recording would be too recognizable. Parents use it in nurseries, travelers use it in hotel rooms, and people in apartments use it to cover the bass from a neighbor's speakers, which brighter colors cannot reach.
Press the play button above to open the generator with the Deep Brown preset loaded. Set the volume so the noise sits just behind whatever you are trying to ignore; if you would need to raise your voice over it, it is too loud. The color slider runs from violet at 0 to brown at 4, so nudging it down toward 3.6 or 3.7 mixes in a little pink and adds some air if pure brown feels muffled.
For sleep, open the sleep timer and choose a duration; the sound fades out gently at the end rather than cutting off. You can install the site as an app on your phone or desktop for offline use, copy the URL to save or share your exact settings, or export a WAV of any length for devices that cannot run a browser.
At a moderate volume, yes. The risk with any sound is loudness, not color. Keep it at a level where you could still hold a conversation over it. Brown noise concentrates its energy in the bass, which is less tiring than the high frequencies in white noise, so many people use it every night.
Both fall off toward high frequencies, but brown noise falls twice as fast: 6 dB per octave instead of 3 dB. Pink noise still has audible hiss and sounds like steady rain. Brown noise sounds like wind or distant thunder with almost no hiss. See the full white vs pink vs brown comparison.
It is named after Robert Brown, who described Brownian motion in 1827, not after the color. Brown noise is a random walk: each sample is the last one plus a random step, which is the same mathematics as a particle being jostled in a fluid. It is also called red noise, which is a color analogy for its low-frequency emphasis.
Many adults with ADHD report that it helps them focus, and the trend was large on social media in 2022. The controlled research is thin: a handful of small studies on white and pink noise show mixed results, and there is very little on brown noise specifically. It is cheap and harmless to try. Read more on the brown noise and ADHD page.
Yes. The export button renders a WAV file of any duration you choose directly in your browser; a one-hour file is about 600 MB at CD quality. Nothing is uploaded anywhere. If you only need it on this device, installing the site as an app gives you offline playback without a file.
Either works. Headphones deliver the bass more consistently and let you keep the volume lower, but some people find them uncomfortable overnight. A small speaker near the bed is fine too; place it away from your head and keep it quiet. Laptop speakers often cannot reproduce the lowest frequencies, so brown noise can sound thin on them.