Audio Feature Explorer
Explore changes in an audio recording. See charts of sound level and frequency features, then download the measured values.
What do spectral audio features tell me about a recording?
Audio features summarize properties of a signal. RMS and peak describe digital amplitude, centroid summarizes the spectrum’s centre, rolloff describes power concentration, and flatness distinguishes concentrated from broadly spread spectral energy. Plot these measures over time and export the values.
Your recording
On your deviceAnalysis downmixes to mono at 22,050 Hz. RMS and peak use digital full scale. Spectral measures use Hann-windowed 2,048-sample frames; these describe the signal, not a calibrated sound-pressure level.
Inside the signal
Time & frequencyLook closer at what you hear.
Choose a clip and analyse its amplitude and spectral features.
Three simple steps
How to use Audio Feature Explorer
Choose a local audio clip.
Analyse the signal and switch between time-series features.
Inspect the spectrum and export JSON, CSV, or SVG charts.
Common questions
Good to know
Understand the result.
Keep the original.
Is this tool free, and are my files uploaded?
This tool is free with no account required. The work happens in your browser. Your input and files are not sent to a processing server.
What are the limits and details?
Features describe the decoded signal and depend on preprocessing. They are not calibrated sound-pressure or hearing measurements. Downmixing can cancel opposite-phase channels, and frequencies above 11,025 Hz are excluded.
Limits: one recording up to two minutes and 16 MB. Analysis uses mono audio at 22,050 Hz, 2,048-sample Hann windows, and at most 2,000 frames.