How it works
- Drop your audio file. MP3, WAV, FLAC, AIFF, OGG or M4A up to 500 MB — it's decoded locally, nothing is uploaded.
- Read the spectrogram. Frequencies on a log scale from 20 Hz to 20 kHz, time left to right, intensity as color. Hover to read exact frequency and time with band-by-band tips, and play the track to follow the playhead.
- Check the report and export. An automatic analysis sums up band balance, resonance candidates, high-frequency extension and approximate dynamic range — then export the image as PNG.
Features
- 100% in your browser. Your track never leaves your computer — decoding, FFT and rendering all run locally with the Web Audio API.
- Log-frequency display, 20 Hz to 20 kHz. The vertical axis matches how we hear, so bass detail isn't crushed at the bottom of the image. Hover for precise frequency, time and band hints.
- Automatic mix report. Energy balance across frequency bands, detected resonance candidates, high-frequency roll-off (a clue to lossy encoding) and an approximate dynamic range measure.
- Synced playback and PNG export. Listen with a playhead moving over the image, then save the spectrogram as a PNG.
FAQ
Is this spectrogram tool free?
Yes. Anonymous users get 5 free analyses per day across AudioKit's free tools — no account needed. If you need more, AudioKit Premium removes the daily limit. There's no watermark and no feature lock: the free analysis is the full analysis, including the report and the PNG export.
Is my audio file uploaded to a server?
No. The spectrogram is computed entirely in your browser using the Web Audio API: your file is decoded and analyzed on your own machine and never leaves it. The only network call is a tiny anonymous counter that tracks your daily free quota.
Which audio formats are supported?
MP3, WAV, FLAC, AIFF, OGG and M4A files up to 500 MB. That covers everything from a quick phone recording to a full-length lossless master. If your file is in another format, run it through our free audio converter first.
How can a spectrogram help me diagnose my mix?
It shows problems your ears suspect but can't pinpoint: a resonance appears as a thin horizontal line, harsh sibilance as bright bursts between 5 and 10 kHz, hum or broadband noise as a constant carpet, and low-end masking as a dense, smeared bottom. AudioKit also generates a report with band balance, resonance candidates, high-frequency extension and approximate dynamic range.
How do I read a spectrogram?
The horizontal axis is time, the vertical axis is frequency (low at the bottom, high at the top — log scale here, like our hearing), and brightness is intensity: the brighter, the louder. Typical patterns: stacked horizontal lines are the harmonics of a note, a vertical stripe is a transient like a drum hit, a uniform haze is noise, and a hard ceiling around 16 kHz is the signature of lossy encoding.