Free browser FFT tool · no audio upload

Audio spectrum analyzer

Open a local file, use the microphone, run a 440 Hz test or generate pink noise. Inspect frequency peaks in real time. The 440 Hz test is silent; selected files play through your output; pink noise reaches the speakers only when you press Play pink noise.

Ready
No source selected. Choose a file, microphone or test tone.
Pink noise generator · Speakers silent. Play it here and pick Use microphone to measure a speaker or room.
−30 dBFS RMS
Analyzer settingsFFT size, scale, channel, smoothing and averaging
0.70
Resolution —
Dominant frequency—Start an input
FFT peak level—Per-bin magnitude; not RMS, sample peak or SPL
InputNoneSample rate —
Peak tableSpectral peaks; note labels may identify harmonics

Strongest spectral peaks

#FrequencyLevelNearest note
—Waiting——
Privacy: audio samples, filenames and readings stay in this page. Limit: an ordinary microphone is not a calibrated sound-level meter. Pink noise: start at low volume; loud noise can damage tweeters and hearing.