Bright horizontal bands
Sustained tones, harmonics, or resonances that stay near the same frequency.
Free browser tool
Free audio spectrogram generator
Choose an MP3 or WAV and create a detailed magma spectrogram without uploading the track.
Processed on your device.
Your audio never leaves this browser. Nothing is saved after the tab closes.
Local spectrogram lab
48 kHzFFT 4096PNG 1920 × 840
Choose an MP3 or WAV to begin
See what is inside the sound.
The browser will decode the track, measure its frequency content, and create a downloadable magma spectrogram.
This file could not be processed.
The app opens separately. Choose your audio again there if you want to enhance it.
Read the image
Time runs left to right. Frequency rises from bottom to top.
Vertical detail
Transients such as drums, clicks, attacks, and sudden changes across a wide range.
Dark upper region
Very little high-frequency energy, which may be natural or may indicate a rolled-off source.
Dense bright texture
More energy at that time and frequency. It does not automatically mean the sound is better or worse.
FAQ
Audio spectrogram FAQ
Does Sunofix upload my audio to generate the spectrogram?
No. This page reads, decodes, analyzes, and renders the file inside your browser. The audio is not sent to Sunofix or stored after you close or refresh the tab.
Should I use MP3 or WAV?
WAV gives the most stable reference because it is uncompressed. MP3 works well for inspection, but different browsers can decode compressed audio with tiny sample-level differences.
Why is there a five-minute and 100 MB limit?
Decoded audio uses much more memory than the original MP3 or WAV. The limits reduce the chance of a mobile browser closing the tab while the spectrogram is being calculated.
Will this PNG exactly match every other spectrogram tool?
Not pixel for pixel. Windowing, FFT size, time pooling, color mapping, MP3 decoding, and resampling can differ. This generator uses the same core settings as the Sunofix before-and-after view.
Hear a problem too?
A spectrogram shows the track. Sunofix can help clean it.
The app opens separately and does not receive the file selected on this page.