How-to

How to merge two DJ libraries into one

Two laptops, two libraries — or one app, two install histories. Music Library Doctor merges them while keeping every playlist intact.

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The problem

You ended up with two DJ libraries: the laptop you tour with and the home studio rig, or your old Rekordbox install and the new one after a Mac migration. Just copying one master.db over the other overwrites everything. Manually rebuilding playlists in the merged library is hours of work. And duplicates between the two libraries — same song bought twice, ripped twice — multiply the chaos.

How Music Library Doctor does it

1 Install Music Library Doctor on a machine that can see both source libraries (mount the other drive if needed).
2 Add both DJ library locations. MLD detects Rekordbox master.db (encrypted 6+ supported), Serato `_Serato_` folders, and VirtualDJ database.xml automatically.
3 Run the Duplicate Scan in acoustic mode — same songs from both libraries get grouped, the Group Scorer recommends the winning copy.
4 Choose a target library (one of the two, or a fresh location). MLD writes the merged playlist set into the target — Rekordbox master.db, Serato crates, or VirtualDJ database — natively.
5 Verify in the DJ app. Both libraries' playlists are now in one place; duplicates collapsed; nothing was overwritten without a backup.

Supported today

Rekordbox · Serato DJ · VirtualDJ (incl. Favorite Folders) on Windows 10+ and macOS (Apple Silicon + Intel).

Why native integration matters

Merging libraries needs three things to happen together: deduplicate at the audio level (not the filename), preserve every playlist from both sources, and rewrite paths once the files have settled in the target location. MLD does all three coordinately and takes a timestamped backup of each source library before any write. Rekordbox 6+ encrypted master.db is supported on both sides, so neither library needs to be downgraded.

Frequently asked questions

What if the two libraries are different DJ apps?

MLD handles cross-app merges too — Serato library plus a Rekordbox library, merged into either side. See the platform-to-platform conversion guides for the specific direction.

Does it preserve cue points?

Cue/hot-cue preservation depends on each app's format. MLD preserves what the target format supports and documents what it can't carry over before the merge runs.

Will my playlists be duplicated if the two libraries had similar playlist names?

MLD groups same-named playlists during the merge plan. You decide per playlist: combine them, keep both separately, or pick one. The default plan is shown for review before any write.

What about files in two locations on disk?

Run the Folder Consolidation Wizard after the merge to bring all files into one target folder. Playlists get re-pointed automatically in the same pass.

Is the original library safe?

Yes. Both source libraries are read-only by default, and a timestamped backup of any database that gets modified is taken first.