Event
{Event}  Bring a friend (or 2!) and save 50% on passes for MongoDB World! Register now and save >>

Realm

Realm Sync. For reactive, run-anywhere mobile apps.

Keep your data up-to-date across devices, users, and your back end with Realm Sync. Facilitate development and ensure performance in any situation.
Try Free
Read documentation
A layer cake consisting of three layers: the bottom is dark green and labeled Atlas, the middle is bright green and labeled Realm Sync, and the top is a transparent green and labeled Realm Mobile Database.
Store locally and sync globally with MongoDB Realm. With out-of-the-box conflict resolution and networking code, Realm Sync reduces build time while keeping your apps performant and responsive.
A semicircle of two bidirectional arrows linking a blue and green smartphone with a bright green data document.

A shortcut for building real-time sync

Speed up and simplify development. Realm Sync takes care of complexities like error handling, cuts down the amount of required code by 20% or more, and streamlines your application architecture — freeing you up to dream big and build boldly.
A visual representation of a database atop a smartphone. In the background are two clouds and two bidirectional, circular arrows.

Run your apps anywhere

Ensure consistent data and a smooth experience wherever your users may be. Realm Sync bridges the gap between local storage (provided by Realm Mobile Database) and your back end (provided by MongoDB Atlas) to keep data current and accurate.
A green hand taps a smartphone. Immediately above is an icon that says “Auto-Scale,” and to the right is a chart with a cloud at the bottom and a green arrow pointing to the top.

Auto-scale with ease

Built on a serverless architecture, Realm Sync seamlessly auto-scales to support spikes in user demand. In addition, Realm Sync supports MongoDB Atlas’ global, multi-cloud clusters for increased versatility and flexibility.

Feature overview
Learn more
realm_conflict_resolution
Built-in conflict resolution
Ensure data uniformity by merging changes through operational transformation.
realm_mobile_sync
Lightweight, local data storage
Store data on devices with the Realm Mobile Database — and sync with Atlas when connected.
realm_sdk
SDKs for any platform
Build apps for any platform, from iOS to Android to .Net or Node.js, without sacrificing user consistency.
general_security_encryption
Best-in-class privacy and security controls
Encrypt your data in-flight, at-rest, in the cloud, or on your device.

Store + sync data — anywhere

MongoDB Realm Sync is for modern mobile applications with a global user base. Overcome distance and dead zones to keep your apps running and your users happy — under all conditions.
View Documentation
Data sync with less effort
Trim time (and lines of code) with easy-to-use Realm Sync. Keep your app data and user changes consistent across devices and back ends with automatic conflict resolution.
Seamless back end integration
Plug into a scalable, serverless back-end powered by MongoDB Atlas. Outsource infrastructure logistics, auto-scale with user demand, and never worry about standing up servers (or surprise bills) again.
Data sync with less effort
Trim time (and lines of code) with easy-to-use Realm Sync. Keep your app data and user changes consistent across devices and back ends with automatic conflict resolution.
Kotlin
Swift
JavaScript (React Native)
C#
Seamless back end integration
Plug into a scalable, serverless back-end powered by MongoDB Atlas. Outsource infrastructure logistics, auto-scale with user demand, and never worry about standing up servers (or surprise bills) again.
Kotlin
Swift
JavaScript (React Native)
C#
Kotlin
Swift
JavaScript (React Native)
C#

Store locally, sync globally

Learn how leading organizations use Realm Sync to persist data and provide a top-notch user experience.
Cox Automotive logo
Connecting the field to the office
Cox Automotive uses MongoDB Realm to sync data and streamline communications between field technicians and operations teams.
Learn More
Inelo logo
Case study
Building dynamic apps that run anywhere
Learn how Inelo used MongoDB Realm to implement data sync, reduce development, and build real-time apps for drivers.
Read more

Get the most out of Atlas

Power more data-driven experiences and insights with the rest of our application data platform.
atlas_database
Database
Start with the multi-cloud database service built for resilience, scale, and the highest levels of data privacy and security.
Learn more

Start using Realm Sync today

Sync data between local device storage and the backend, simplify development, and ensure app performance — regardless of connectivity.
Try Free
REALM SYNC IS:
  • Serverless
  • Bidirectional
  • Cross-platform
  • Intuitive
  • Scalable