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Sync Overview

Realm Sync automatically synchronizes data between client applications and a Realm App. When a client device is online, the SDK asynchronously synchronizes data in a background thread between the device and the backend.

When you use Sync in your client application, your implementation must match the Sync Mode you select in your backend App configuration. The Sync Mode options are:

  • Partition-Based Sync
  • Flexible Sync

You can only use one Sync Mode for your application. The Kotlin SDK only supports Partition-Based Sync.

See Also

Enable Realm Sync

Partition-Based Sync​

When you select Partition-Based Sync for your backend App configuration, your client implementation must include a partition value. This is the value of the partition key field you select when you configure Partition-Based Sync.

The partition value determines which data the client application can access.

You must provide a partition value when you open a synced realm.