Spectrogram Generator
Visualize the frequencies in an audio file over time as a high-resolution spectrogram image.
Add audio
MP3, WAV, M4A, OGG, FLAC, OPUS — or a video to pull audio from.
Choose an output
Visualize the frequencies in an audio file over time as a high-resolution spectrogram image.
Fine-tune
Optional — sensible defaults are already set.
About Spectrogram Generator
A spectrogram shows which frequencies are present in a recording over time, with time on one axis, frequency on the other and color for intensity. This tool renders one as a PNG with a choice of color palettes and optional axes and legend.
When it helps
- Checking whether a FLAC or high-bitrate MP3 is a genuine lossless or high-quality file, or an upscaled low-bitrate copy
- Spotting hum, whine or noise bands before cleaning a recording
- Looking at bird song, speech or instrument harmonics for study or teaching
- Finding hidden images or messages embedded in audio puzzles
Tips
- A hard cutoff in the high frequencies, often around 16 kHz, is a typical sign of a low-bitrate MP3 that was converted to a lossless format.
- Leave 'Show axes & legend' on when you need to read frequencies and times; turn it off for a clean image.
- Magma and Viridis are easy to read and stay clear in grayscale print. 'Per channel' colors left and right differently.
- A wider image gives finer time detail on long files.
Good to know
Quick answers about spectrogram generator in your browser.
Generate a spectrogram and look at the top of the frequency range. True CD-quality audio usually has content up toward 20 kHz, while a transcoded MP3 often shows a sharp shelf around 16 to 19 kHz.
Brighter or warmer colors mean more energy at that frequency and moment. Dark areas are quiet. The legend shows the exact scale.
Yes. There is no sign-up, no watermark and no limit on how many files you process.
No. Files are read and processed locally in your browser, so they never leave your device.
Related tools
Part of the Audio Effects & Tools collection.