When syncing — Replace server data or Replace local data?

• Replace server data — pushes your local 2Do tasks up to the sync service. Use this when 2Do has the right data and the server is empty or out of date.
• Replace local data — pulls tasks from the server down to this device. Use this when the server has the right data.

Pause before choosing. If your device is empty and you choose Replace server data, the empty device can overwrite the cloud copy. Always pause and think about which side has the data you want to keep before confirming. When in doubt, share / export a backup first.

Where to set this any time

Beyond the automatic first-sync prompt, you can pick the next sync's behavior manually whenever you need it:

• iPhone / iPad / Android — Settings > Sync > Next Sync Action.
• Mac — 2Do > Settings > Sync > Next Sync Action.

Dropbox and CalDAV offer Sync normally, Replace server data, and Replace local data before triggering a sync. Toodledo offers Sync normally, Replace local data, and Merge sync. After the sync completes, the option resets to Sync normally automatically.

Use Merge sync only when you need to combine local 2Do data with Toodledo data. It may create duplicates if both sides already contain the same tasks and lists.

Common recovery pattern

If one device has the correct 2Do data and another device is missing tasks or out of sync, use the good device as the source of truth:

1. On the device with the most accurate data, create a backup first.
2. On that same device, set Next Sync Action to Replace server data.
3. Trigger a manual sync and let it finish. This pushes that device's 2Do data up to the sync service.
4. On each out-of-sync device, set Next Sync Action to Replace local data.
5. Trigger a manual sync on each out-of-sync device. This replaces that device's local copy with the data from the sync service.

Do not choose Replace server data on an empty or stale device. That can overwrite the good server copy with bad data.