A content-based hash of the audio signal itself — stable across formats, bitrates, and tag spellings. It's what makes cross-format duplicate detection possible.
Filename-based duplicate detection misses duplicates with different filenames. Metadata-based detection misses duplicates with different tags. The same recording stored as `Artist - Title (320).mp3` at 320 kbps and `artist_title_192.mp3` at 192 kbps looks like two completely different files to any tool that compares names or tags. The only way to know if two files contain the same recording is to look at the audio itself — and that's what acoustic fingerprinting does.
Supported today
Rekordbox · Serato DJ · VirtualDJ (incl. Favorite Folders) on Windows 10+ and macOS (Apple Silicon + Intel).
The power of acoustic fingerprinting is invariance: the fingerprint stays nearly the same when you re-encode, re-tag, or rename a file, because the audio itself stays nearly the same. That makes it the only reliable way to catch cross-format duplicates and re-encoded copies of tracks you've already had for years. MLD layers it with the Group Scorer so you don't have to manually compare every group — the best copy is highlighted automatically.
A file hash (MD5, SHA256) changes when even one bit changes — different encoder, different tag, different bitrate all produce different hashes. An acoustic fingerprint is stable across those changes because it summarizes the audio content, not the file bytes.
No. The fingerprint reflects the actual audio — different mixes, different masters, and remixes all produce different fingerprints. Only acoustic-twin copies match.
Chromaprint produces a fingerprint; matching it to a specific song name requires a database lookup (MusicBrainz, AcoustID). MLD uses Chromaprint locally for duplicate detection without lookups — the fingerprint comparison is what matters for dedup. Online identification is a separate optional feature.
Roughly 5–10 seconds per track on a modern machine, since the audio has to be decoded. A 10,000-track library finishes in 10–30 minutes; results are cached so subsequent scans are instant.
No. Fingerprints are computed locally and stay local. MLD never uploads audio or fingerprints.
Free tier covers detection and viewing. Lifetime access is $49 — $19 for the first 100 DJs.
