White Noise Generator
Mask distracting sounds, fall asleep faster or focus at work. Play white, pink, brown, blue, violet or grey noise, blend several colors, soften the tone and let the sleep timer fade it out for you.
How to use the White Noise Generator
- Pick a quick mix such as Deep sleep or Focus, or switch on the colors you like in the mixer.
- Press Play noise. Adjust each color's slider while it plays to find your blend.
- Shape the sound with the Tone slider: lower values make any noise warmer and softer.
- Set the sleep timer if you want the noise to fade out and stop by itself.
- Keep the volume moderate and press Stop when you're done.
Noise colors compared
| Color | Spectrum slope | Sounds like | Often used for |
|---|---|---|---|
| White | Flat (0 dB/octave) | TV static, air vent, fan | Masking speech, baby sleep, audio testing |
| Pink | −3 dB per octave | Steady rain, rustling leaves | Sleep, focus, acoustic measurements |
| Brown (red) | −6 dB per octave | Waterfall, strong wind, rumble | Deep sleep, relaxation, ADHD focus playlists |
| Blue | +3 dB per octave | Hissing water spray | Dithering in audio mastering |
| Violet | +6 dB per octave | Very high, thin hiss | Tinnitus masking experiments |
| Grey | Follows an inverse equal-loudness curve | Even, neutral rush | Psychoacoustics, tinnitus masking |
"Per octave" means each doubling of frequency. Pink noise has half the power per hertz at 2,000 Hz that it has at 1,000 Hz, but the same power in every octave band, which is why it sounds balanced to our ears.
How the noise is generated
- White: independent random samples between −1 and 1.
- Pink: white noise through a set of first-order filters (Paul Kellet's method), accurate to about ±0.05 dB above 9 Hz.
- Brown: a leaky running sum of white noise, bn = (bn−1 + 0.02·wn) ÷ 1.02, which integrates the signal and gives the −6 dB/octave slope.
- Blue and violet: the difference between consecutive samples of pink and white noise, which tilts the spectrum upward by 6 dB/octave.
- Grey: white noise boosted at low and very high frequencies and cut around 3.5 kHz, where hearing is most sensitive.
Each color is normalized to the same average level, so switching colors doesn't cause sudden jumps in loudness, and the 8-second loops are crossfaded so you never hear a seam.
Safe listening levels
Noise for sleep or focus works best when it's just loud enough to cover distractions. As a rule of thumb, keep it below about 60 dB at your ears, roughly the level of a normal conversation, and lower for babies. Hearing damage risk starts with long exposure above 80–85 dB. If you use headphones, start with the volume low and turn it up slowly.
Frequently asked questions
What is the difference between white, pink and brown noise?
White noise has equal energy at every frequency, so it sounds bright and hissy. Pink noise drops by 3 dB per octave and sounds more balanced, like steady rain. Brown (Brownian or red) noise drops by 6 dB per octave and sounds deep, like a waterfall or distant thunder.
Which noise is best for sleep?
There is no single best color; it's personal. Many people find brown or pink noise more pleasant than white noise for sleeping because it has less high-frequency hiss. Try the Deep sleep mix and lower the Tone slider if it still sounds too bright.
Is white noise safe for babies?
Pediatric guidance generally suggests keeping white noise for infants quiet, around 50 dB (the level of a quiet shower), placing the device well away from the crib and not playing it at full volume all night. Use the sleep timer and a low volume. This tool is not a medical device.
Does it work in the background or with the screen off?
On computers it keeps playing when you switch tabs. On phones, some browsers pause audio when the screen locks or the browser is in the background; keep the page open, or plug the phone in and let the screen dim instead of locking it.
How does the sleep timer work?
Choose a duration before or while playing. A countdown appears on the spectrum display, the noise fades out over the last 30 seconds (if Fade out is ticked) and then stops completely.
Is the noise really random?
Yes. Every color is generated in your browser from random numbers and filtered mathematically into its color, then looped seamlessly. There are no audio files to download, so it starts instantly and uses no data.