White, Pink & Brown Noise
Pick a sound, press play. Loops forever, generated live in your browser.
White, pink or brown noise?
White noise has equal energy at every frequency, like a hiss or a fan — good for masking speech. Pink noise has more energy in the low frequencies, like steady rain, and many people find it softer. Brown noise is deeper still, like a strong waterfall or distant thunder, and is a common choice for focus and sleep.
Tips
- Keep the volume low enough to talk over it comfortably.
- Use the sleep timer so the sound stops by itself after you fall asleep.
- On phones, keep the screen on or the tab open; some browsers pause sound in the background.
FAQ
Is this safe for babies?
Keep any sound machine at a low volume and well away from the baby’s ears. Ask your pediatrician about recommended levels.
Does it use data?
No. The noise is generated on your device, so there is nothing to stream after the page loads.
Why is there no sound?
Check your device volume and silent switch, then press Play again — browsers only start audio after you click.
How to use the noise generator
- Choose a Sound. The page opens on brown noise, the deepest of the three, with the volume at 40%.
- Set the Sleep timer if you want one: 15 minutes, 30 minutes, 1 hour, 2 hours or 8 hours. Leave it on Off to play until you stop it.
- Press Play. The button turns into Stop, and when a timer is set a countdown such as "Stops in 29:41" appears next to it.
- Move the Volume slider at any time. It changes the level live without interrupting the sound.
Changing the Sound or the Sleep timer while audio is playing restarts playback with the new choice, and the timer countdown starts again from the full length you picked. Set the timer before you press Play if you want the countdown to be exact.
What the page actually does to make the sound
Nothing is downloaded. When you press Play the page asks your browser's Web Audio engine for a four-second mono buffer and fills it, sample by sample, with random numbers. That buffer is then set to loop for as long as you listen. Each of the three sounds is a different recipe applied to the same stream of random values:
- White: each sample is a random value between -1 and 1, halved. Every sample is independent of the one before, which is why the energy is spread evenly across the spectrum and the sound is bright and hissy.
- Brown: each new sample is built from the previous one plus a small random step (a leaky running sum), and the result is scaled up. Because successive samples are strongly related, slow movements dominate and fast ones are weak. The result is a low rumble with very little hiss. The name comes from Brownian motion, not from the colour.
- Pink: white noise is passed through a bank of simple filters whose combined effect tilts the balance toward the low end. It lands between the other two: softer than white, lighter than brown.
Technically the three differ in how fast the power falls as frequency rises. White stays flat, pink falls by about 3 dB per octave and brown by about 6 dB per octave. In practice that means pink is a good match for steady rainfall or wind in leaves, and brown for a distant engine or a heavy river.
Why the loop does not click
A four-second recording repeated forever can produce a faint tick every time it wraps around. To prevent that, the first 2,000 samples of the buffer are blended with the last 2,000, so the end flows into the start. At typical sample rates of 44.1 or 48 kHz this blend lasts roughly 40 to 45 milliseconds. Because the noise is random, the loop has no melody or pattern to recognise; some listeners with sensitive ears may notice a very slight rhythm every four seconds with white noise. If so, switch to pink or brown, which hide it better.
Choosing a sound for the job
- Masking a noisy room or neighbours: white noise covers the high frequencies of speech and traffic best. Start quiet and raise the volume only until the sudden sounds stop standing out.
- Studying and reading: pink or brown at low volume gives your attention something steady to ignore. Try a session of each and keep whichever you stop noticing fastest.
- Going to sleep: brown at a low level, with the 30-minute or 1-hour timer, is a common starting point. Use 8 hours only if you want it on all night.
- Tinnitus or racing thoughts: many people simply find a constant sound easier to live with than silence. This is personal preference, and the tool makes no medical claim.
Tips and limits
- The sleep timer stops the sound at once when it reaches zero. There is no gradual fade-out, so choose a volume you can sleep through.
- Browsers only allow audio after a click or tap, which is why the page never starts on its own.
- The sound is generated again each time you press Play, so no two sessions use exactly the same buffer.
- Laptop and phone speakers cut off the lowest frequencies, so brown noise may sound thinner than it does on headphones or a larger speaker. Do not turn the volume up to compensate.
- Some mobile browsers suspend a tab's audio when the screen locks or you switch apps. If the sound stops, return to the tab and press Play again.
More questions
Is brown noise the same as red noise?
The two names are used for the same kind of noise, the one whose power drops steeply as frequency rises. "Brown" is the more common label for sleep and focus audio.
Why does the sound change when I switch type?
Switching builds a brand-new buffer with a different recipe and restarts playback, so you hear a short break rather than a smooth morph. The volume setting is kept.
Does it work without a connection?
After the page has loaded, yes. The audio is synthesised in your browser, so a dropped connection will not interrupt it.