Audio Spectrogram - Free Online | FunToolX
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Spectrogram
Decode audio and draw a spectral heatmap (x=time, y=frequency, color=intensity).
About this tool
Audio Spectrogram is a free online tool. Generate a spectrogram heatmap showing frequency over time.
After uploading the audio file, the tool uses Short-Time Fourier Transform (STFT) to divide the audio into multiple short periods, and performs FFT transformation on each period to obtain the frequency component at that moment. Arrange the spectrum of all time periods vertically to form a spectrum diagram. The horizontal axis is time, the vertical axis is frequency, and the color depth represents energy intensity.
The resolution of the spectrogram depends on the window size and overlap rate. The larger the window, the higher the frequency resolution but the lower the temporal resolution. The tool provides parameter adjustments: window size (256-8192), overlap ratio (50%-95%), colormap (heat map, viridis, gray scale, etc.).
Suitable for analyzing formants of speech, harmonic structure of music, and frequency distribution of environmental noise. It is widely used in speech recognition, music information retrieval, and acoustic ecology research. You can export the spectrogram to PNG, or export the raw data to NumPy format.
An audio spectrogram generator converts audio into a time-frequency analysis chart and displays the changes of frequency components over time for sound analysis and visualization.