White noise generator
White noise has a flat power spectrum: equal power per hertz. Its bright, steady hiss makes a useful starting point for comparing the other colours.
Explore white noiseFree browser player · No ads · No signup
Noise generator: four colours.
Hear the difference.
White, brown, pink and green noise in one generator. Switch colour while it plays to compare the sound with a short crossfade.
White
Noise generatorReady to play White
Sleep timer
Timer off
Brown noise generator
Brown noise slopes down by roughly −6 dB per octave. It puts more energy in the low frequencies, giving it a deep, rumbling texture.
Explore brown noisePink noise generator
Pink noise slopes down by roughly −3 dB per octave, with equal power per octave. It sounds less bright than white noise, with more weight in the lower frequencies.
Explore pink noiseGreen noise generator
Green noise describes noise with a mid-band emphasis. There is no formal standard for green noise, so its sound varies between generators.
Explore green noiseWhat this does not do
This generator does not diagnose or treat anything. The timer is a convenience, not a sleep protocol.
Slo is also an app
Available for iOS, Android and Mac.
Frequently asked questions
Is this noise generator free?
Yes. This browser player is free, with no ads and no signup. Choose a colour and press Play.
Can I switch noise colour while it plays?
Yes. Choose another colour during playback for a short crossfade. Switch back and forth to compare their textures without stopping playback.
How does the sleep timer work?
Choose 15, 30 or 60 minutes. The countdown starts with playback and continues across colour switches. Pausing cancels the countdown; pressing Play starts the selected duration again. Off cancels the timer.
Can I layer noise with other sounds?
This page compares one colour at a time. The browser mixer lets you combine sounds and adjust the volume of each layer.