Brown Noise Generator
Short answer
This is a free brown noise generator that runs in your browser. Press play and your browser makes the sound live, as you listen, instead of playing a file on repeat. There is no account and nothing to download. A browser tab stops when your phone locks, so for all-night play use the BRW app.
What Is Actually Happening When You Press Play
Nothing was downloaded to make that sound. No audio file was fetched, nothing is streaming, and if you go offline now it will keep going. When this page loaded, your browser got a small set of instructions for how to make brown noise. It has been making it ever since, many thousands of times a second, for as long as you leave it on.
That is the difference between a generator and a player, and it is why this page is separate from the rest of the site. Most things called a brown noise generator are an audio file on repeat. This one really is a generator: a source of random numbers, a filter that shapes them into brown noise, and maths that runs as you listen.
If you want to know what brown noise is (how it differs from white and pink, what it covers well, and what the research really supports), that is a different question, and it has its own page. This page is about the tool.
A Real Generator, or a Looped File in Disguise?
This is the question to ask of any noise site. Here is the honest answer for this one, including the part that is a limit, not a boast.
In current browsers there is no loop at all. Modern browsers let a page run its own sound code as you listen. The generator runs there. It makes each small piece of sound when it is needed, plays it, and throws it away. Nothing is replayed, because nothing is stored. Leave it on for eight hours and no second repeats an earlier one. The question "can you hear the loop?" simply stops applying.
In old browsers there is a backup, and it does loop. If your browser cannot run the generator, the page makes 30 seconds of noise in advance and plays it round and round. It is built so the end joins the start without a click. But it is a loop, and a page that said otherwise would be lying. In practice this affects only browsers from before about 2018. If yours is up to date, you are on the generator.
And we checked it, not just assumed it. The brown noise page has more on this. In short: we measured the sound, and it gets steadily quieter as the pitch goes up, exactly as true brown noise should. Every colour on this site also plays at the same loudness, so changing colour never means reaching for the volume.
If You Came Looking for a Download
Some people come here looking for a brown noise file to download. There isn't one. That is a choice, not an oversight, so here is why, and what to do instead.
This site used to offer a small MP3 file. We replaced it with the generator, for the reason above. A downloaded file has a fixed length, so over a night it must repeat. Ten hours of sleep from a two-minute file is three hundred repeats, and the ear is very good at learning a pattern it hears three hundred times. A generator has no such limit.
For one session, this page is the download. Once it has loaded, the generator runs completely on your device. Turn off wifi and it keeps going, because there is nothing left to fetch. That is what most people wanted a file for.
For all-night or offline use, install the app. A browser tab cannot keep playing once your phone locks. The phone pauses the tab, and that stops the sound. A better web page cannot fix this. It is a rule that applies to every website, and it is why sleep apps are installed, not bookmarked. The app plays with the screen off, works with no connection at all, and has a sleep timer. It is free on Android and on iPhone.
There is no email wall here and no file to unlock. If you want the sound now, it is above. If you want it all night, it needs to be an app, and that is true of every noise website you will find.
How to Catch a Looping Generator in About Two Minutes
This is worth knowing in general, because anyone can call their site a "generator", and most sites that do are playing a file. None of these tests need special equipment beyond headphones, and all of them work on this page as well as on any other.
Listen for a landmark. Real noise sometimes throws up something faintly different, such as a swell or a moment that sits lower than the rest. Fix on one, then wait. If it comes back at a regular interval, you have found the loop. Loops are usually 10, 30 or 60 seconds long, so two minutes of attention catches almost all of them.
Check what the page downloads. Open your browser's developer tools, go to the Network tab, and reload the page. A generator downloads a small script and nothing more. A player downloads an audio file, and you will see its name and size in the list. This test gives a clear answer.
Go offline after it starts. Turn off wifi thirty seconds in. Anything streaming will run out and stop. A downloaded file will keep playing, and so will a generator. So this test alone cannot tell those two apart.
Be suspicious of a download button. Downloads are not bad. But a real generator has nothing to put behind one. If a site offers both, the file is the real product and the generator is decoration.
Try the first two tests on this page if you like. The Network tab will show a script and no audio, and the landmark test will not find anything, because there is nothing to find.
Getting Something Useful Out of It
Headphones, or a speaker that plays good bass. This matters more for brown noise than for any other colour, because most of its sound is too deep for a phone or laptop speaker to play. Through a phone, you hear only the thin top of it, and turning the volume up only makes the thin part louder. Many people who decide brown noise is not for them have only heard it played badly.
Set the volume against the noise you want to cover, not against silence. The sound should sit just above the noise you want to hide, and no higher. Louder does not cover better. Past a point, you just swap one disturbance for another, and you spend the night at a volume that is not kind to your ears.
Give it five minutes. In the first thirty seconds, any noise feels like an intrusion. Whether it works is a question for minute four, when you have stopped listening to it and it has started doing its job.
Sessions last 30 minutes. The counter on the player shows your free time. It is one allowance for the whole site, so opening a second page does not give you another half hour. In the last minute the sound fades out slowly instead of stopping suddenly, because sudden silence can wake you too.
Try the other colours before you decide. Which one suits you depends on what you want to cover, and you cannot know in advance. Brown for traffic rumble and machines, white or green when the problem is voices through a wall, and pink as a middle ground. They all run on this same generator, so the comparison is fair.
What This Page Cannot Do
It will not keep playing when your phone locks. This is worth saying again, because it is the most common disappointment with any noise tool in a browser. Lock the screen or switch to another app, and the phone pauses the tab, which stops the generator. No website is an exception. So this works if you fall asleep with the phone awake and charging next to you, but it will not carry you to morning.
It needs JavaScript. A generator in a browser cannot work with JavaScript turned off, because the maths is the sound.
It will not mix with rain or thunder. You get one colour at a time here. Mixing sounds is an app feature, mostly because playing several sounds in a browser tab all night is not a good plan.
It is not a treatment for anything. Tinnitus and ADHD each have a page here, and each has less evidence behind it than this whole category likes to suggest. The same is true of insomnia. If your sleep has been bad for weeks, the useful next step is to see a doctor. No generator or app changes that.
If You Only Read One Paragraph
This is a real generator. Your browser makes brown noise live as you listen, and on any current browser there is no loop. We measured it, and it behaves exactly as true brown noise should. It is free, it needs no account, and there is nothing to download. Turn off your connection after it starts and it keeps going. Use headphones, set the volume just above the noise you want to cover, and give it five minutes before you judge it. If you want it all night with the screen off, you need an installed app, and ours is free on both stores.
Frequently Asked Questions
Is this brown noise generator free?
Yes. No account, no email address, no trial and nothing to close. Press play and it works. Sessions last 30 minutes, and that time is shared across the whole site, so opening another page does not reset it. The free app removes the limit and adds things a browser cannot do, such as playing with the screen off.
Does this generator loop?
On any current browser, no. There is no loop at all. The sound is made as you listen, and each small piece is thrown away after it plays, so nothing is replayed and no second repeats an earlier one. There is one exception. If your browser is very old, roughly from before 2018, the page plays a 30-second piece of noise round and round instead. That piece is built to join without a click, but it is a loop.
Can I download a brown noise file instead?
There is no file to download here, on purpose. A downloaded file has a fixed length, so over a night it has to repeat. Ten hours from a two-minute file is three hundred repeats, and the ear learns a pattern it hears that often. The generator has no such limit. For one session, this page is really the download, because once it has loaded it runs on your device with no connection. For all-night use, install the app. A browser tab cannot keep playing once the phone locks.
Does it work offline?
Once the page has loaded, yes. The generator runs completely on your device, so turning off wifi after it starts changes nothing. There is nothing left to fetch. What it cannot do is keep playing when the phone locks or when you switch to another app. Phones pause background tabs, and that stops the generator. For real offline use all night, you need an installed app.
How accurate is the brown noise?
We checked it, not just claimed it, and the brown noise page has more detail. In short, we measured the sound, and it gets steadily quieter as the pitch goes up, very close to perfect brown noise. It also plays at the same loudness as every other colour on the site.
Which browsers does it work in?
Any current browser on a computer or a phone: Chrome, Safari, Firefox and Edge all work. JavaScript has to be turned on, because the maths is the sound. Very old browsers still play, but they use a 30-second loop that joins without a click, instead of making the sound live.
Is this the same brown noise as the app?
The sound is the same. Trying it here is a good way to find out if you like brown noise before you install anything. What is different is everything around the sound. The app plays with the screen off and while you use other apps, and works with no connection. It has a sleep timer that fades out instead of cutting off, mixes brown noise with rain and thunder, and has all five noise colours.
Why does the sound fade out after 30 minutes?
That is your free session time running out. The sound fades down over the last minute instead of just stopping, because sudden silence can wake a light sleeper. The half hour is one allowance for the whole site, so moving to another page will not give you a new one. The free app has no session limit.
Can I use it for something other than sleep?
Yes. In every case, the honest use is sound masking: covering one sound with a steadier one, so your brain stops noticing it. Think of an open-plan office, a shared study space or a thin wall. Brown noise suits low noises such as traffic and machines. When you want to cover speech, a brighter colour usually works better. That is why white, pink, green and blue are all on this site, and all run on this same generator.