Realm is a mobile database that runs directly on Android devices as a replacement for SQLite and traditional ORMs.
Realm addresses the friction of mobile data persistence by embedding a database engine directly into the application rather than requiring network calls or complex object-relational mapping layers. The tool exposes data as queryable objects in code, eliminating the performance and maintenance overhead associated with ORMs. It handles thread-safety, relationships, and encryption natively, and performs faster than raw SQLite on common operations while maintaining a rich feature set.
Developers building Android applications should consider Realm if they want to reduce boilerplate and improve query performance compared to SQLite-based approaches. The project maintains a deliberately minimal API surface, allowing developers to become productive quickly. However, the README explicitly recommends that new projects use the Realm Kotlin SDK instead, which supports both Android and Kotlin Multiplatform. The Java version is no longer the primary focus for new development.
The project carries a significant deprecation notice: Atlas Device Sync and the Realm SDKs were announced as deprecated, with users directed to migration documentation. This signals that the Java SDK is in maintenance mode rather than active feature development. The README actively steers new projects toward the Kotlin alternative, indicating a strategic shift in the platform's direction.
