White Noise Generator

White noise has the same power at every frequency, so the band from 40 to 60 Hz holds as much sound as the band from 400 to 420 Hz. Your ears pick up the high end most, which is why it sounds like a bright hiss.

Pink noise loses 3 dB every time the frequency doubles, so each octave carries the same energy. It sounds softer, like steady rain. Brown noise drops 6 dB per octave and sounds like a deep rumble, closer to a waterfall or distant thunder. It is named after the botanist Robert Brown and Brownian motion, not the color.

Green noise has no agreed definition. Here it is white noise filtered around 500 Hz, which keeps the middle and rounds off the hiss and the deepest rumble.

The sound is made in your browser the first time you press Play, so there is nothing to download. Each color is a 10-second stereo loop with its end blended into its start, so you don't hear a click every 10 seconds. It is still a loop, not an endless random stream.

All four colors are matched for loudness, and the volume fades in and out when you start, stop or switch, so nothing jumps. The Sleep timer stops the sound after 15 minutes, 30 minutes, 1 hour or 2 hours, fading out over the last 30 seconds.

Black screen covers the page in black so a phone or laptop by the bed doesn't light up the room. Tap it, or press Enter or Esc, to close it. Phones treat a locked screen differently, so if yours stops the sound when it locks, leave the screen on with Black screen instead.

People play noise to cover other sounds: traffic, a neighbor's television, a partner who snores. If white noise sounds too sharp, try brown or pink, which keep more of the low end.

The research is thinner than its popularity. A 2021 review of 38 studies rated the evidence that continuous noise improves sleep as very low quality. So treat it as a sound you like falling asleep to, and keep the volume low.

That matters most for babies. A 2014 study in Pediatrics measured 14 infant sleep machines at full volume, and every one was louder than 50 dBA at 30 cm, the limit recommended for hospital nurseries. Keep the volume down and the speaker away from the cot.

Noise is one of the biggest searches in the sleep space. In the US, Google's Keyword Planner shows about 246,000 searches a month for white noise, 90,500 for brown noise and 33,100 for green noise.

That makes noise and ambience a good place to start a channel. Chillframe makes the calm music or ambience, the visual and the finished video, at any length up to an hour, and publishes it to YouTube on the days you pick. Ambience here means pure background sound, like rain, with no music in it.