White noise is noise with equal energy at every frequency you can hear, the audio equivalent of white light holding every visible color at once. On greensound it's generated live in your browser as plain random samples, one per sample of audio, with no filter or shaping applied afterward — the flattest, brightest of the four noise colors here.
Why is it called white?
Same idea as white light, which is every visible color combined rather than one color on its own. White noise carries equal energy across every audible frequency instead of favoring any one part of the range, which is the audio version of that same combination. The name describes how its energy is spread, not a literal sound of the color white.
Why does white noise sound so bright?
Frequency doubles with every octave: the octave from 400 Hz to 800 Hz spans twice as many hertz as the one from 200 Hz to 400 Hz, and each higher octave spans twice as many hertz as the one below it. White noise spreads equal energy across every hertz, so the wider higher octaves end up carrying more of the total sound than the narrower lower ones. That's why an evenly spread signal like this reads as treble-heavy to the ear rather than balanced.
White noise or pink noise?
Pink noise starts from the same random samples as white noise and runs them through a filter of six parts added together, so its level falls about 3 dB for every octave up in pitch, where white noise's stays flat across the whole range. Side by side, pink has proportionally less at the top of the range than white does, so it reads as less bright.
Is white noise the same as static?
Only in texture, not in how it's made. What plays here is generated directly in your browser from random numbers, one per sample, with no antenna, radio or other hardware involved anywhere in the chain.
Where the sound comes from
White noise. Made in your browser, not a recording.
Listen safely
This is a sound, played back through whatever speaker or headphones you already own. It doesn't diagnose, measure, or promise anything about how you sleep, focus, or feel — it's just noise and a handful of real recordings, mixed the way you like them.
Keep the volume low enough that you'd still notice a smoke alarm, a phone ringing, or someone at the door. If you fall asleep in headphones, choose a volume and a pair you'd be comfortable wearing all night, and a session length that ends when you'd want the sound to stop.
If you use this near a baby, keep the speaker several feet from the crib, never inside or clipped to it, and keep the volume low — the same care you'd take with any sound machine in a nursery.
If your relationship with sound, or with sleep, feels difficult rather than simply restless, a doctor or audiologist is the right person to talk to. This is a mixer, not a clinician.
What exactly is white noise?
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It's a signal that carries equal energy at every frequency across the range you can hear, the audio equivalent of white light containing every visible color at once. That even spread is what gives it its flat, bright, hissy character, compared with green or brown noise, which weight their energy toward the middle or the low end instead.
Can I run white noise at the same time as a real recording?
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With Pro, yes. The mixer supports up to six sounds at once, each with its own volume, so white noise can sit alongside night wetland, beach waves or any other sound here. Without Pro, one sound plays at a time.
Is white noise part of the free plan?
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Yes, fifteen minutes a day. This sound is free to play for fifteen minutes a day, with a fade at the end, and Pause keeps the minutes you have left. Pro adds the full mixes, layering, longer timers, and new recordings first.
How loud should it be?
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Loud enough to notice, quiet enough that you could still hear someone talking to you from across the room without straining.