Audio Spectrum Analyzer

See the frequency content of a file or your microphone as live bars on a canvas.

See the frequencies in your audio

Hold peaks Logarithmic axis

Status: Choose a file or the microphone

Source: None

Dominant frequency: —

FFT size: 2048

The analyser runs on the Web Audio API and draws straight to a canvas, so your audio never leaves the browser.

Common questions about the free online audio spectrum analyzer.

Choose an audio file with the file picker, then press play on the player. The bars update live and show how much energy sits in each frequency band.

Yes. Click Use microphone and allow access, then the bars follow whatever the microphone hears, which is handy for tuning rooms and instruments.

It is the strongest frequency bin in the current frame, shown in hertz or kilohertz. A pure tone appears as a single tall bar at that frequency.

The analyser uses 2048 samples. A larger FFT separates nearby frequencies better, but it updates a little more slowly and uses more memory.

Peak hold keeps a marker at the highest level each band has reached and lets it fall slowly, so short bursts of sound are easier to see.

It spreads the low frequencies out and squeezes the high ones, which matches how human hearing works and makes music easier to read.

No. The file is decoded by your browser and processed by the Web Audio API on your device, so nothing is sent to a server.

Yes. The analyser works in any modern mobile browser, and microphone access works on phones as long as you allow the permission prompt.

Last updated: October 10, 2026