White noise, done right.

What is white noise?

White noise is sound that contains every audible frequency at equal intensity — the audio equivalent of white light. To the ear it sounds like steady static, a hard rain on a roof, or an untuned radio. Because it covers the whole frequency spectrum at once, it acts like an acoustic blanket: sudden sounds (a door, a car horn, a snoring partner) stand out less against it, which is why so many people use it to fall asleep, stay asleep, or focus in noisy places.

Research on noise as a sleep aid is genuinely promising but not settled. A 2021 systematic review in Sleep Medicine Reviews (Riedy et al.) found that continuous noise can improve sleep onset in noisy environments, while calling for better-controlled studies. In other words: it clearly helps many people, it is low-risk and free to try, and anyone promising miracles is overselling it. Our approach on this site is to let you test it yourself — the generator above is the whole experiment.

White, pink, brown — the colors of noise

Not all noise is white. Pink noise rolls off the harsh high frequencies, so it sounds softer — closer to steady rainfall or wind through trees. Brown noise goes further and concentrates its energy in the low end: think waterfall, ocean swell, or the rumble of an airplane cabin. Many people who find white noise fatiguing over a full night sleep better with pink or brown. If you want the deep-end version, start with our brown noise guide.