Audio Comparison Tool — MFCC, Spectrogram & Waveform
Upload two audio files and DiffALL compares them using the same psychoacoustic features used in speech recognition. See the mel spectrogram difference and the exact second each divergence starts.
Free, no sign-up — your files never leave the comparison.
Drop file here or click to browse
MP3 · WAV · FLAC · AAC · OGG · M4A · OPUS · WMA
Drop file here or click to browse
MP3 · WAV · FLAC · AAC · OGG · M4A · OPUS · WMA
Comparing two different recordings of people talking to see if it's the same person? Use the Voice Comparison tool →
Free to use — no sign-up needed
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API Keys
One key for the whole DiffALL API — compare two files, or check the quality of one — from scripts and CI. Each call costs one credit.
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What DiffALL measures
MFCC Similarity
Mel-Frequency Cepstral Coefficients capture the timbral fingerprint of a sound — the same features used in speech recognition and music retrieval.
Spectral Centroid
Measures the perceived 'brightness' of each file — detects EQ changes, high-frequency roll-off, and tonal shifts.
RMS Energy
Root Mean Square energy comparison detects loudness normalisation differences, dynamic range compression, and volume automation.
Mel Spectrogram
Side-by-side mel spectrograms and a JET-coloured difference map let you see frequency-over-time divergences visually.
Per-Second Breakdown
MFCC similarity charted second by second — spot the exact moments two audio files diverge.
Hear the Difference (Null Test)
Lines the two files up to the sample, matches their levels and subtracts one from the other — what is left is exactly what changed, as a track you can play and download.
Supported formats
Use cases
Podcast QA
Compare the raw recording to the edited version to confirm only the intended cuts were made.
Music Mastering
Verify a mastered track against the mix to quantify what the mastering chain changed.
Encoding Tests
Compare a lossless FLAC to an MP3 or AAC encode to measure quality loss at different bitrates.
Restoration QA
Compare a noise-reduced or restored file to the original to hear and measure exactly what the processing removed.
Frequently asked questions
How do I compare two audio files for differences?
Upload any two audio files to DiffALL. It resamples them to a common rate, computes MFCC, spectral centroid, and RMS energy similarity, and displays mel spectrograms with a difference overlay.
What audio formats does DiffALL support?
MP3, WAV, FLAC, AAC, OGG, M4A, Opus, and WMA. Audio is compared up to 2 minutes at a time on every plan — for a longer recording, up to 3 minutes, you choose which 2 minutes. Files up to 40 MB on the free plan, 100 MB on Pro.
What does the MFCC similarity score mean?
MFCC similarity is a correlation coefficient from 0 to 100%. 100% means the timbral content is identical. Scores above 90% suggest the files are perceptually very similar; below 70% indicates significant tonal differences.
Can DiffALL compare audio at different sample rates?
Yes. Both files are resampled to a common rate (capped at 22,050 Hz) before comparison, so sample rate differences don't affect the result.
Can I do a null test online?
Yes. After a comparison, press Make the difference track. DiffALL lines the second file up with the first to the sample, matches its level and polarity, and subtracts it, at the files' own sample rate and in stereo. Whatever is the same cancels; you can play and download what is left, see where in the recording it is, and read how far below the music it sits. A one-sample offset or a 0.2 dB level change — the usual reasons a null test done by hand fails — are corrected first and reported.
Ready to compare audio files?
Free, no install, no sign-up required for your first comparison.
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