Welcome to the Realm Docs
Realm is a mobile-first database designed for modern, data-driven applications. You can use Realm to build mobile, web, desktop, and IoT apps.
Realm is an embedded, object-oriented database that lets you build real-time, always-on applications. Its SDKs also provide access to Atlas App Services, a secure backend that can sync data between devices, authenticate and manage users, and run serverless JavaScript functions.
Realm has open-source SDKs available for most popular languages, frameworks, and platforms. Each SDK is language-idiomatic and includes:
The core database APIs for creating and working with on-device databases.
The APIs you need for connecting to the App Services backend so you can make use of server-side features like Device Sync, Authentication, Functions, Triggers, and more.
Atlas App Services
Discover how to sync data, define permissions, and connect to other services, including MongoDB Atlas.
Swift SDK
Build applications in Swift or Objective-C for Apple platforms, including iOS, macOS, watchOS, and tvOS.
Kotlin SDK
Build cross-platform applications for Android, iOS, and macOS with Kotlin Multiplatform (KMP). Realm data maps directly to the classes in your app.
.NET SDK
Build applications that use C# and the .NET platform, including MAUI, Xamarin, native Windows applications, and Unity projects.
Node.js SDK
Use the Node.js SDK to build server and IoT applications in JavaScript or TypeScript.
React Native SDK
Use the React Native SDK to build cross-platform applications in JavaScript or TypeScript.
Java SDK
Build Android applications in Java or Kotlin. Realm data maps directly to the classes in your app.
Web SDK
Build web applications in JavaScript or TypeScript. Access data with GraphQL and MongoDB queries.
Flutter SDK
Build Flutter applications with Dart.
C++ SDK
Build applications in C++. Access data stored in realms and sync data with Atlas.
For legacy (pre-v10) Realm Documentation, see https://www.mongodb.com/docs/realm-legacy/docs/.