Quick answer
Each Soundiiz Sync runs in one direction: from one source playlist to one destination playlist. It is not a bidirectional mirror.
When the Sync runs, Soundiiz reads the source playlist and updates the destination using the selected method:
- Add: add source tracks that are not already in the destination.
- Replace: replace the destination tracklist with the matched source tracks.
A Sync is for playlists only. It does not synchronize Liked Songs, favorite tracks, albums, artists or an entire music library.
How does the Sync direction work?
The source and destination have different roles:
- Source: the playlist Soundiiz reads at each execution.
- Destination: the playlist Soundiiz updates.
Changes made in the destination are not sent back to the source by that Sync. Soundiiz does not merge changes made independently on both sides.
One Sync slot connects one source playlist to one destination playlist. To send the same source playlist to several destinations, create a separate Sync for each destination.
What is the difference between Add and Replace?
Add
Add keeps the current destination playlist and appends matched source tracks that are not already present.
- Tracks removed from the source are not removed from the destination.
- Tracks added directly to the destination remain there.
- Soundiiz checks the destination before adding tracks, but different releases or versions of the same song can still appear separately.
Choose Add when the destination should keep its existing tracks and grow over time.
Replace
Replace rewrites the destination tracklist using the tracks currently found in the source playlist.
- Destination tracks that are not in the source are removed.
- The source track order is recreated when the destination service allows it.
- Tracks that cannot be matched in the destination catalog are skipped.
Choose Replace when the destination should follow the source as closely as the destination catalog allows.
Important: Replace changes the destination playlist. Check the selected source, destination and method before saving the Sync.
Which frequencies are available?
A Sync can run:
- Daily
- Weekly
- Monthly
Soundiiz reads the source again at each scheduled execution. A transfer made after creating the Sync does not define future results; the current source playlist does.
How can I create a Sync?
From a playlist
- Open Playlists under Your Library.
- Open the source playlist's three-dot or contextual menu.
- Select Sync with....
- Choose the destination music service.
- Select an existing destination playlist or create a new one.
- Choose Add or Replace, then select the frequency.
- Review and save the Sync.
From My Syncs
- Open My Syncs under Automation.
- Select Synchronize playlists.
- Choose the source playlist.
- Choose or create the destination playlist.
- Select the method and frequency, then save.
What does Run now do?
Run now requests an immediate execution instead of waiting for the next scheduled run. It does not change the source, destination, method or normal frequency.
Run now is available with paid plans and may be temporarily unavailable when another Sync is already running toward the same destination music service. YouTube and YouTube Music share the same execution queue.
See how Run now works.
Why is the destination not an exact copy?
Soundiiz can only add tracks available in the destination catalog. A track may be skipped because it is unavailable, region-restricted or listed with different metadata.
Replace therefore recreates the source as closely as possible; it cannot guarantee an identical result across different music services.
How many Syncs can I create?
Each source-to-destination Sync uses one Sync slot. The number of available slots depends on the current Soundiiz plan and any additional slots attached to the account.
Free accounts include limited access for testing. Paid plans include more Sync slots and access to additional Sync controls. Check the current Soundiiz plans and Sync allowances.
Before enabling a Sync
- Confirm that the correct playlist is selected as the source.
- Confirm that Soundiiz can edit the destination playlist.
- Choose Add or Replace according to what should happen to destination-only tracks.
- Review advanced options before allowing an empty source to affect the destination.
- Create a backup if the destination playlist contains tracks you may need to restore.
Browse the Soundiiz tutorials for service-specific transfer and Sync instructions.