Noise Generator
Generate white, pink, brown, blue, or violet noise in your browser: up to 30 minutes. Pick a duration, sample rate, channels, and loudness; export as wav, mp3, aac, ogg, or opus. Perfect for sleep, focus, ASMR, UGC voice-over beds, and tinnitus masking. No upload, no signup.
Interactive tool
-12 dBFS recommended for UGC voice-over beds; -6 dBFS for standalone listening.
What is the Noise Generator?
A free, in-browser noise generator that synthesises white, pink, brown, blue, or violet noise of any length up to 30 minutes. Output is true PCM: no recordings, no samples, no licensing, generated locally in your browser and exportable as wav, mp3, aac, ogg, or opus. Built for sleep / focus / ASMR creators, UGC background beds, baby white noise, and tinnitus masking.
How to Use the Noise Generator
- 1Pick a noise color (white, pink, brown, blue, or violet)
- 2Pick a target duration: 60 s for a quick test, 10-30 min for sleep / focus beds
- 3Choose sample rate (44.1 / 48 kHz), channels (mono / stereo), and loudness
- 4Optional: add a fade-in and fade-out for a soft start / end
- 5Pick an output format: wav is instant and lossless, mp3 / opus are smaller for sharing
- 6Click Generate, preview, then download
Key features
Five noise colors
White (flat), pink (-3 dB/oct, sleep favourite), brown (-6 dB/oct, deep rumble), blue (+3 dB/oct, masking), violet (+6 dB/oct, treble-only)
True stereo decorrelation
Two independent generators per channel: produces the spacious "around your head" sound, not a flat mono duplicated to L/R
Up to 30 minutes per render
Chunked PCM streaming sidesteps the OfflineAudioContext memory wall. Multi-hour sleep beds are on the roadmap as a server-side option
Loudness in dBFS
A proper -30 to 0 dBFS slider with -12 dBFS recommended for UGC voice-over beds: no surprise clipping
Optional fade-in / fade-out
Smooth attack and release for clean starts / endings under a voice-over, intro, or outro
Five output formats
wav (lossless, instant), mp3 / aac / ogg / opus (re-encoded via ffmpeg.wasm) with a bitrate slider
100% private
The noise is synthesised in your browser. No upload, no signup, no logs.
Why Generate Noise Locally?
Free noise-generator sites usually loop a short pre-recorded sample (so you hear the join), or upload a long render through their server (slow, watermarked, privacy-hostile). Generating noise locally produces a fresh, statistically continuous stream of any length: no loops, no joins, no watermark, no upload. You get exactly the seconds you asked for and the bytes never leave your browser.
Common use cases
- Long-form sleep / focus bed (10-30 minutes of pink or brown noise)
- Baby white noise loops for car seats, strollers, and bedrooms
- Tinnitus masking at a calibrated low loudness
- UGC voice-over background bed under a TikTok / Reel / podcast intro
- Sound-design starter for synth pads, swells, and impacts
- Test signal for speaker / room / headphone tuning
What is the difference between white, pink, and brown noise?
White noise has equal energy per hertz: a flat spectrum that sounds bright and "hissy", like radio static. Pink noise has equal energy per octave (-3 dB/oct), which matches how the ear weights frequency. It sounds balanced and is the most-recommended for sleep and focus. Brown noise (-6 dB/oct) emphasises low frequencies further. It sounds like deep rain, surf, or a distant waterfall and is popular for ADHD focus. Blue (+3 dB/oct) and violet (+6 dB/oct) reverse the slope: useful for masking high-frequency tinnitus or as a dithering / test signal.
Sample rate, channels, and loudness: what to pick
48 kHz is the standard for video work (TikTok, Instagram, YouTube). 44.1 kHz is the music / podcast standard. Stereo with the "independent generators" mode gives a spacious sound on headphones; mono is fine for in-ear or speaker playback. For a voice-over bed, -18 to -12 dBFS keeps the noise well under the voice. For standalone listening, -12 to -6 dBFS is comfortable. Above -6 dBFS risks clipping on cheap playback gear.
How the noise is synthesised
White noise is uniform Math.random() scaled to amplitude. Pink uses the Voss-McCartney 7-row summing algorithm (the standard real-time pink-noise generator). Brown uses a leaky integrator over white noise to prevent DC drift. Blue and violet apply first- and second-order differentiators to white noise. All five run in pure JavaScript in 1-second chunks so memory stays flat: no OfflineAudioContext, no Web Audio dependency, no chance of OOM on long renders.
Looping the output in a video editor
Most editors (CapCut, iMovie, Premiere, DaVinci Resolve) loop audio cleanly when the file is true noise. There is nothing to phase-mismatch. Drop the wav onto your timeline and right-click → Loop. For TikTok / Reels uploads, mp3 or aac at 192 kbps is the right balance of file size and quality.
Tips & best practices
Pick pink for sleep, brown for focus
Pink noise is the most-recommended for falling asleep. It tracks the ear's natural frequency weighting. Brown noise is the popular pick for ADHD focus because the bass weight masks distracting transients.
Use wav for sharing with sound designers
Lossless wav is the right deliverable when someone else will re-encode it. For end-user playback, mp3 / opus at 128-192 kbps is indistinguishable from wav and is much smaller.
Set loudness to -12 dBFS for UGC
A -12 dBFS noise bed sits cleanly under most voice recordings without ducking. For pure ambient listening, -6 dBFS is closer to "comfortable foreground" level.
Choose stereo for headphone listening
The independent-generators stereo mode decorrelates the two channels, producing the "around your head" effect. Mono noise sounds flat and dead-center on headphones.
Privacy & security
Noise generation runs entirely in your browser. Nothing is uploaded, logged, or stored. ffmpeg.wasm engine artefacts are served from our own origin (not a third-party CDN).
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- Audio Looper
Loop a short audio clip into a long one (up to 30 minutes) in your browser. Pick a target duration, get a seamless crossfade by default, or use byte-perfect Fast mode for pure noise sources. Powered by ffmpeg.wasm. No upload, no signup.
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Frequently Asked Questions
What is the difference between white, pink, and brown noise?
White noise has equal energy per hertz: bright and hissy, like radio static. Pink noise has equal energy per octave (-3 dB/oct), which matches how the ear weights frequency, so it sounds balanced and is the favourite for sleep. Brown noise (-6 dB/oct) emphasises low frequencies further: deep rain, surf, or a distant waterfall, and is popular for ADHD focus. Blue (+3 dB/oct) and violet (+6 dB/oct) reverse the slope: useful for high-frequency tinnitus masking, dithering, and test signals.
Is brown noise good for ADHD focus?
A lot of ADHD creators and researchers find brown noise easier to work to than white or pink: the bass-heavy spectrum masks distracting mid-range sounds (notifications, conversation) without the brightness of white noise. Try 10-30 minutes at -12 to -18 dBFS under a focus session and see what works for you. This tool ships brown noise as a first-class option.
Can I use this for baby white noise?
Yes. Generate 10-30 minutes of white or pink noise at a moderate loudness (around -12 dBFS) and download as wav or mp3. Loop the file in your phone or speaker app. The output is true PCM: no audible loop join, no compression artefacts, no licensing concerns.
Can I loop the output in CapCut, iMovie, or Premiere?
Yes: all major editors loop wav and mp3 files cleanly. For a longer bed than this tool will generate in one render, drop the file on the timeline and right-click → Loop. Because the output is pure noise (no melodic content), the loop join is inaudible.
Is the WAV output actually lossless?
Yes. The WAV format is 16-bit signed PCM with no compression: every sample is exactly the float we synthesised, clipped to the 16-bit range. There is no encoding pass involved. Re-encoding to mp3 / aac / opus is offered for smaller file sizes but is optional.
Why is duration capped at 30 minutes?
A 30-minute stereo 48 kHz wav is around 330 MB: close to the limit of what most browsers can hold in a Blob while keeping the tab responsive. Multi-hour sleep / ASMR renders are on the roadmap as a server-side option that will stream the output instead of buffering it.
Does this upload anything?
No. The noise is synthesised in your browser with pure JavaScript. ffmpeg.wasm (used only when you pick a non-WAV format) runs locally too. The bytes never leave your device. ffmpeg artefacts are served from our own origin under /ffmpeg/<version>/.