How to analyze sound with a spectrogram
- Drop an audio file to play it through the analyzer, or press “Use microphone” for live input.
- Watch the scrolling spectrogram, or switch to the Spectrum view for a real-time frequency curve.
- Tune the FFT size, colour intensity and log/linear frequency scale to reveal the detail you need.
- Press “Save image (PNG)” to export the current view for notes, reports or sharing.
This online spectrogram turns sound into a picture so you can see what you are hearing. Load a track or open your microphone and the display scrolls in real time, with a brand-tinted colour map running from dark navy for silence up through red to warm white for the loudest frequencies. Engineers use it to hunt down hum and hiss, vocalists check sibilance and breath noise, musicians study the harmonics of an instrument, and the curious simply watch their voice paint the screen. Adjustable FFT size trades timing against frequency detail, the log scale matches how we perceive pitch, and a PNG export captures any moment. Everything runs locally in your browser, so it is private, instant and free.
FAQ
What is a spectrogram and how do I read one?
A spectrogram shows how the frequency content of a sound changes over time: the horizontal axis is time, the vertical axis is frequency, and brighter, warmer colours mean more energy at that frequency. Reading it lets you spot harmonics, hiss, hum, sibilance and the shape of notes or speech at a glance.
Can I make a spectrogram from my microphone?
Yes. Press Use microphone and allow access, and the spectrogram scrolls live as you speak, sing or play. You can also drop in an audio file and it animates in sync with playback, so you can analyse recordings as well as live input.
What do the FFT size and frequency scale controls do?
A larger FFT size gives finer frequency detail but coarser timing; a smaller one does the opposite, so 1024 is good for fast transients and 8192 for tonal detail. The log scale spreads out the low and mid frequencies the way we hear them, while linear gives equal spacing across the whole range.
Can I save the spectrogram and is anything uploaded?
Press Save image to export the current view as a PNG. Nothing is uploaded — the file or microphone signal is processed entirely in your browser with the Web Audio API, so your audio never leaves your device and the tool is completely free.