BYTETOOLS

Audio Spectrogram Generator

Generate a spectrogram image from any audio file online for free. Visualize frequency content over time and download a PNG — 100% in your browser.

Drop an audio file here or click to browseThe spectrogram is computed locally — your audio is never uploaded.

What is the Audio Spectrogram Generator?

The Audio Spectrogram Generator renders a spectrogram — a heat-map of frequency content over time — from any audio file.

  • Full-file spectrogram with time and frequency axes
  • Multiple color schemes (intensity, fire, rainbow and more)
  • Optional legend with labeled axes and dB scale
  • 1024×512 or 2048×1024 output resolution
  • 100% local — audio is never uploaded
  • PNG download for reports, teaching or analysis

How to use the Audio Spectrogram Generator

  1. 1

    Drop an audio file onto the box or click to browse.

  2. 2

    Pick an image size and color scheme, and choose whether to include the axis legend.

  3. 3

    Click Generate Spectrogram and wait for the analysis.

  4. 4

    View the spectrogram and download it as a PNG.

About the Audio Spectrogram Generator

The Audio Spectrogram Generator renders a spectrogram — a heat-map of frequency content over time — from any audio file. Time runs left to right, frequency runs bottom to top, and color intensity shows how much energy each frequency has at each moment.

Spectrograms reveal things a waveform cannot: the exact frequency of a hum or whine, whether an 'MP3 upgrade' really contains high frequencies or was upscaled from a low bitrate, bird calls and speech formants, and even images hidden in songs by electronic artists. Audio engineers, students, and curious listeners all use them.

The FFT analysis and image rendering run entirely in your browser through WebAssembly ffmpeg's showspectrumpic filter — professional-grade output with no uploads, no server and no account.

Frequently asked questions

How do I read a spectrogram?

Time runs along the horizontal axis and frequency along the vertical axis, usually with low frequencies at the bottom. Brighter colors mean more energy. A flat horizontal line is a constant tone or hum; vertical stripes are clicks or drum hits.

Can a spectrogram tell if a music file is really high quality?

Often, yes. Lossy encoders discard the highest frequencies first, so an MP3 re-encoded from a 128 kbps source typically shows a hard energy cutoff around 16 kHz even if the file claims 320 kbps. A genuine high-bitrate or lossless file shows content extending toward 20 kHz.

What is a spectrogram useful for?

Finding the frequency of hums and noise so you can filter them, checking recordings for clipping and bandwidth, analyzing speech and birdsong, teaching acoustics, and spotting hidden images that some artists embed in their tracks.

Why does the top of my spectrogram look empty?

The audio simply has little energy at those frequencies. Most musical content lives below 10 kHz, and lossy files often have nothing above 16–19 kHz. An empty top band is normal, not an error.

Is my audio uploaded for analysis?

No. The spectrogram is computed and drawn entirely in your browser using a WebAssembly build of ffmpeg. Your file never leaves your device.

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