Audio Analyzer
One overview of everything measurable in a file, to find out what is wrong with it.
MP3, WAV, M4A, FLAC, OGG, Opus, AIFF, WMA, AMR and the sound of most videos. Files stay on your device.
How it works
- Choose an audio file.
- Wait for the analysis to finish.
- Read the summary, then explore the charts.
What the analysis covers
The analyzer reads the whole file once and reports what can be measured: sample peak, RMS level, crest factor and DC offset for each channel, true peak, integrated loudness, loudness range and the loudest short moments, stereo phase correlation and the level change when the file is played in mono, an estimate of dynamic range, the average spectrum and the number of clipped samples. A short summary at the top turns those numbers into plain sentences, such as "clipping found" or "not mono compatible".
Nothing is uploaded. The file is read in pieces by your browser, so long files do not need much memory, and a progress bar with a Cancel button shows while it works.
Reading the charts
The waveform shows level over time. The average spectrum shows how much energy sits at each frequency, from 20 Hz to the top of the range, on a logarithmic axis. The spectrogram thumbnail shows frequency over time; open it in the spectrogram viewer to zoom. Each chart has a text alternative: the spectrum has a table of octave-band levels, and the loudness graph has a table of values over time.
The effective bandwidth is an estimate, not a fact. It is the highest frequency that still carries content within 60 dB of the strongest part of the average spectrum. A file that stops near 16 kHz may come from an MP3 or from an upsampled recording, but quiet recordings, acoustic music and speech can also have little energy up high. Treat it as a reason to look closer, for example in the spectrogram.
Limits to keep in mind
Loudness follows ITU-R BS.1770-4 and EBU R128 with a true-peak reading from a 4 times oversampled signal. The dynamic range figure is a DR-meter-style estimate (the peak against the loudest fifth of three-second blocks), so it will not match a certified DR meter exactly. Phase correlation is for stereo files; mono files have none.
The report can be saved as JSON for scripts, CSV for spreadsheets or plain text.
Questions
Is my file uploaded?
No. The analysis runs in your browser on your device, and the page makes no requests with your audio.
Why does it say my file may be upsampled or from a lossy source?
The average spectrum drops sharply well below half the sample rate. Lossy encoders cut high frequencies, and a file converted up from a lower sample rate has nothing above the old limit. It is a heuristic and can be wrong for naturally dark recordings.
What counts as clipping here?
Three or more samples in a row at or above -0.01 dBFS. The clipping detector tool lets you change the threshold and the run length and lists where the clipping is.
Does a long file take much longer?
Analysis time grows with the length of the file, roughly in step with decoding it. A progress bar shows how far it has got, and you can cancel at any time.