Realm Java SDK
On this page
- Develop Apps with Realm
- Install the Realm Java SDK
- Define an Object Schema
- Open a Realm
- Read and Write Data
- React to Changes
- Connect to an Atlas App Services App
- Authenticate a User
- Open a Synced Realm
- Read and Write Synced Data
- Call Serverless Functions
- Query MongoDB Atlas
- Authenticate Users
- Recommended Reading
Realm is now Atlas Device SDK – Learn More
Use the Realm Java SDK to develop Android apps in Java or Kotlin. To develop multiplatform apps using Kotlin Multiplatform Mobile, refer to the Realm Kotlin SDK.
What You Can Do
Develop Apps with Realm
Use free open-source Realm as a local object store on a device. Use Device Sync to keep data in sync with your MongoDB Atlas cluster and other clients.
Essential Documentation
Recommended Reading



Kotlin Extensions API Reference
Explore generated reference docs for the Kotlin Extensions APIs.