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Sync devices

Tsumu syncs one macOS collection with one Android phone over a network you control. The Mac runs the server; the phone starts each sync. Two desktops do not sync directly. The Windows sync workflow has not been verified against the current core; see Windows status.

Before you start

Use a trusted local network. The sync server listens on the Mac’s network interfaces and has no login or authentication. While it is running, another device that can reach its address can send sync requests, including requests involving collection rows and media. Do not forward its port to the internet or run it on an untrusted shared network. Stop the server when you finish.

Connect the phone

  1. On the Mac, open Settings → Sync Server → Start Server. Keep Tsumu open and note the displayed IP address and port, usually 8080.
  2. Connect Android to the same trusted network. Tap the round Sync button and enter the Mac’s displayed IP address and port. Check the port shown on the Mac rather than relying on the phone’s prefilled value.
  3. Tap Sync and wait for upload, download, verification, and media transfer to finish. The address is remembered for next time.
  4. Sync before switching devices and again after changing cards or reviewing. The Mac does not pull changes on its own.

What moves

Cards, deletions and restores, review history, study logs, card snapshots, preferences, and card images and audio move in both directions. The first connection exchanges the collections; later syncs transfer changes. Preferences such as desired retention, fitted FSRS parameters, and the day boundary timezone sync as rows.

If the same card row was changed on both devices before sync, the later recorded edit wins for that row, so an earlier edit can be replaced. Review answers are stored as separate rows and are added independently. Syncing before and after switching devices reduces conflicts.

If sync fails

  • Server and address: Check that the sync server is started on macOS and note the IP address and port displayed (usually 8080). Home Wi-Fi routers may reassign IP addresses upon reconnecting.
  • Local Network Permissions (macOS): On macOS 15 (Sequoia) or later, check System Settings → Privacy & Security → Local Network and ensure Tsumu is permitted to communicate on the local network.
  • Wi-Fi isolation: Public Wi-Fi or guest networks frequently enforce "client isolation" or "AP isolation," blocking phones and laptops from communicating directly. Use a home network or personal mobile hotspot if devices cannot ping each other.
  • Verification mismatches: If verification reports a mismatch, tap Sync again to retry. Large initial syncs with extensive media files can take a few minutes over Wi-Fi. Always stop the server once sync completes.