Free Online Player
Brown Noise
Press play for instant brown noise in your browser — no download, no signup, no account. The deep, steady rumble is generated live and loops for as long as you need it to help you focus, relax, or drift off to sleep.
Slo is a brown noise app for iPhone, Android and Mac, with free browser players like this one and a mixer at slonoise.com — layer brown noise under rain at whatever levels suit you, on a timer. Our guide to the best brown noise apps compared ranks the alternatives side by side.
Ready to play
Stack this under rain or a fire, keep the blend, and play it with your screen off. Slo, on iOS, Android and Mac.
What is brown noise?
Brown noise (also called Brownian or red noise) is a type of sound signal with far more energy in the low frequencies than in the high ones. Compared with the flat hiss of white noise or the balanced sound of pink noise, brown noise drops off more steeply as pitch rises, giving it a deep, rounded character. To most listeners it sounds like a powerful waterfall, heavy surf, or the muffled roar of a jet cabin — full and steady, without the sharp treble that some people find fatiguing.
Why brown noise helps focus and sleep
The reason brown noise works so well is masking. Sudden changes in your environment — a door closing, a notification, a voice down the hall — are what pull your attention or wake you up. A constant, broadband sound raises the background floor so those spikes no longer stand out, keeping your brain in a stable, even soundscape. Because brown noise emphasizes lower frequencies, many people find it warmer and less harsh than white noise for long listening sessions, whether that means a deep-work block, a study stretch, or a full night of sleep.
It is also a genuinely low-effort tool: there is nothing to learn and nothing to install here. Press play, set a comfortable volume, and let the sound run in the background. If you are using it for sleep, set the timer so playback stops on its own once you have drifted off. Keep the volume moderate — loud enough to cover distractions, quiet enough to stay comfortable over hours.
Learn more
If you want to go deeper, explore our guides on the best sounds for focus, the science behind brown noise, and the top Noisli alternatives if you are looking for a full-featured app. Brown noise is one of many colors of noise, and the right one for you may depend on whether you are trying to concentrate, unwind, or sleep through the night.
This browser player generates a single stream of brown noise. For a full sound library you can mix and match — brown noise layered under rain, a crackling fire, or ocean waves, each with its own volume — try the Slo app on iOS, Android, and Mac.
Frequently asked questions
What does brown noise sound like?
Brown noise is a deep, steady sound with more energy in low frequencies. Many listeners compare it to a powerful waterfall, heavy surf, or the muffled roar inside a jet cabin.
Can brown noise help with focus or sleep?
Brown noise can mask sudden environmental sounds that interrupt concentration or sleep. Its warmer, lower-frequency character may also feel less harsh than white noise during long listening sessions.
What volume should I use for brown noise?
Use a moderate, comfortable level: loud enough to soften distracting sounds, but quiet enough to listen to comfortably for an extended period.
Does this brown noise player have a sleep timer?
Yes. You can set the free browser player to stop automatically after 15, 30, or 60 minutes, or leave the timer off for continuous playback.