signal noise explorer — free browser tool | fatcousin

white · pink · brown · raf jitter · mic ambient — same axes · interactive comparison · runs locally

noise source

white = equal power per Hz · pink = equal power per octave (−3 dB/oct) · brown = random walk (−6 dB/oct) · raf jitter = scheduling noise · mic = environmental ambient

control

why this matters

noise colour determines behaviour. pink noise sounds more natural to humans than white; brown noise sounds like wind. the −3 dB/octave slope of pink noise is also the slope of most natural time series including stock prices, heart rate, and earthquakes.
raf jitter is not white noise. the browser’s requestAnimationFrame scheduler has memory — it tries to hit 16.67 ms exactly but misses in a correlated way when the main thread is busy. the autocorrelation stat above reveals this.
ambient mic audio contains structure. hvac hum at 50/60 hz, fan noise, and traffic produce coloured spectra. a true anechoic chamber comes close to white.
the distinction matters for security. a crypto random number generator must produce white noise (autocorr ≈ 0). if autocorrelation is non-zero, the sequence is predictable.