Free online green noise generator

What is green noise?

Green noise concentrates its energy in the middle of the audible range, broadly around 500 Hz, with the deep bass and the high hiss both rolled away. Where white is flat and brown is bottom-heavy, green is a hump in the middle and quiet at both ends.

It is worth being straight about one thing: green noise is not a formally defined engineering term the way white, pink and brown are. There is no standard slope for it. It is a useful description of a mid-focused band of noise, and different apps draw the boundaries slightly differently, so what you hear here is our reading of it rather than a specification.

What this green noise is designed to mask

The mid-range is where speech, footsteps and household movement mostly sit, so green noise covers the sounds that actually interrupt a household while adding no weight to the room at all.

That absent bass is the whole point, and the reason to choose it deliberately. Brown noise travels: low frequencies pass through walls and floors far more readily than high ones, so if you share a wall, live above someone, or have a partner who objects to a rumble in the room, green does the masking job without any of that. It is also the color to reach for if brown noise makes you feel like there is pressure in the room.

The flip side is a real limitation. Green cannot mask what it does not overlap, so a passing truck, a boiler or upstairs footfall will come straight through. If low rumble is your actual problem, use brown instead.

How loud should you set it?

Green noise has a specific trap. Because there is no bass in it, it feels thinner and quieter than it measures, and the instinct is to push the volume up to compensate for a weight that was removed on purpose. Resist that. Judge it only on whether the disturbance has stopped pulling your attention, not on whether the sound feels substantial.

The honest check for green is whether the specific thing bothering you has stopped surfacing. It will never fill a room the way a bass-heavy color does, and waiting for that feeling will only push it too high. The full three-step method is here.

How this generator actually works

Because green noise has no agreed definition, sites offering it are usually serving one particular recording of one particular interpretation. This page generates it in your browser instead, using a port of the generator that runs inside the Veil app, so you can hear the shaping described below rather than take it on trust.

It starts from the same Paul Kellet cascade that produces pink noise, with slightly more unshaped white mixed back in. The shaping is then aggressive at both ends: two high-pass stages at 380 Hz for a decisive bass cut, since one is not steep enough to really clear the low end, and a low-pass at 3.6 kHz to take off the hiss. What survives is the middle.

Two independent cascades run in buffers of about 30 and 37 seconds, with coprime sample counts, and are mixed together, so the combined pattern takes roughly 1.55 years at 44.1 kHz to realign. Each loop boundary is crossfaded against real continuation samples rather than faded to silence.

Try the other colors.

Which color works is personal, and a minute of listening settles it faster than any chart. Each of these is a live generator like this one: White noise Pink noise Brown noise Grey noise Blue noise. Or hear all six side by side. If noise is not the right texture, there are also seven fan sounds.

Green noise for sleep, in depth