MongoDB vs. Couchbase: Comparing Mobile Database Features

MongoDB is deprecating its Atlas Device Sync and Atlas Device SDKs. Here’s what to know if you’re considering migrating to Couchbase Mobile.

Today’s mobile app users expect an always fast, always on, personalized and engaging experience. It’s imperative for app adoption and growth, and any failure to meet these expectations pretty much dooms your apps to abandonment.

But guaranteeing a fast, always available experience becomes a challenge if the database that powers the app runs only in the cloud. Because mobile users are constantly moving in and out of network coverage, if they lose the connection, the mobile app slows or fails outright.

To ensure a continuous, speedy user experience where internet connectivity is spotty, mobile developers often leverage mobile database platforms. These platforms combine a cloud database with an embedded database that runs on-device within applications. The embedded data processing makes apps faster and more reliable by eliminating the need for an internet connection to a distant cloud database; it instead uses the local data to power the app.

However, the cloud database is still crucial as a central data aggregation point for mobile apps. Therefore, data synchronization is another critical component of a mobile database platform, as nearly every app needs to share data between users and/or to the cloud for consistency.

Because of these capabilities, mobile database platforms are popular with mobile app developers who want to ensure their apps are fast and available without dependencies on the internet.

The playing field narrows

The mobile database platform options for mobile developers have just gotten fewer. In September 2024, MongoDB announced the deprecation of its mobile database platform Atlas Device Sync and Atlas Device SDKs (formerly known as Realm), to the dismay of many mobile developers. Developers have until September 2025, when support officially ends, to find alternatives.

Now that developers must move to a new platform, examine how MongoDB’s mobile support compares to an alternative mobile database platform, Couchbase Mobile.

Comparing Couchbase Mobile to MongoDB Atlas

Both solutions offer a cloud NoSQL database backend, embedded data persistence for mobile apps and data synchronization, but that’s about where the similarities end. While there are many differences between the two platforms at a granular level, here are a few of the major ones:

Database schema flexibility

• • Atlas Device SDKs (Realm) is object-oriented, which has advantages, but also requires a schema to model relationships. This creates rigidity, which increases the complexity of applications.
  • Couchbase Mobile is schemaless — it’s a classic JSON document database, which makes it more flexible. For example, doing things like adding new fields and indexes doesn’t disrupt a rigid schema, and this can make things like app upgrades faster, easier and more efficient.

SQL support

• • Atlas Device SDKs require a proprietary API and syntax that does not support joins and aggregations, so developers must work around these limitations in code.
  • Couchbase Mobile supports SQL++ from the cloud database to the on-device database, meaning you use the same queries across the app ecosystems. SQL support also makes Couchbase straightforward for developers to adopt.

Vector search

• • MongoDB only supports vector search in Atlas, making it dependent on internet access to work. That means if there’s no internet, there’s no vector search.
  • Couchbase Mobile supports vector search both in the cloud database and in Couchbase Lite running on the device. That enables offline-first edge AI features, helping to future-proof apps and add AI features.

Data sync

• • MongoDB’s sync solution does not support peer-to-peer sync. This means it cannot sync without an internet connection to Atlas, and it does not support custom conflict resolvers.
  • Couchbase Mobile provides peer-to-peer sync, enabling data sync to happen via peer-to-peer access between local devices without needing an internet connection or central cloud control point. Couchbase Mobile also allows developers to create their own custom conflict resolution policies.

Device platform support

• • Atlas Device Sync primarily supports mobile device platforms such as Android, iOS, React Native and .NET.
  • Couchbase Mobile supports all of the above platforms and offers the C API, which allows developers to embed data processing to resource-constrained Internet of Things (IoT) devices on single-board computers like Arduino and Raspberry Pi.

Migrating to Couchbase Mobile from MongoDB Atlas

No database migration is ever 100% smooth. The effort inevitably throws curveballs into the most well-thought-out plans. If you are considering a move to Couchbase Mobile from MongoDB Atlas Device Sync/Atlas Device SDKs, we’ve created a host of resources to help make it as easy and straightforward as possible:

• • This matrix provides a granular, feature-by-feature comparison of Couchbase Mobile vs. MongoDB Atlas Device Sync/Atlas Device SDKs.
  • This technical blog provides an in-depth guide to the considerations and approaches for migration, including data modeling, data migration and application migration. It’s an essential read for anyone starting a migration effort from MongoDB Atlas Device Sync/Atlas Device SDKs to Couchbase Mobile.
  • This on-demand webcast with Couchbase partner MOLO17 details how GlueSync helps easily move data from MongoDB Atlas to Couchbase Capella for Couchbase Mobile migrations.
  • And this Atlas Device SDK to Couchbase Lite Comparison Guide on GitHub goes in-depth into each SDK’s comparable functionalities, including Android, .NET, Objective-C and Swift.

Conclusion

At Couchbase we see our mobile capabilities as a strategic differentiator, and we have hundreds of customers using the platform for their high-scale mobile apps, including PepsiCo, Emirates, Lotum and AutoCrib. We are committed to being a leader in mobile database applications and will continue to evolve our capabilities for powering offline-first mobile and IoT apps.

The post MongoDB vs. Couchbase: Comparing Mobile Database Features appeared first on The Couchbase Blog.