RxDB vs. SQLite vs. WatermelonDB vs. python-sql Comparison Chart

​RxDB is a local-first, NoSQL JavaScript database optimized for modern web and mobile applications. It enables offline-first functionality by storing data directly on the client using storage engines like IndexedDB, OPFS, SQLite, and more. RxDB offers real-time reactivity, allowing developers to subscribe to changes in documents, fields, or queries, ensuring that UI components update automatically as data changes. Its flexible replication engine supports syncing with various backends and custom endpoints. RxDB integrates seamlessly with frameworks and environments. Additional features include field-level encryption, schema validation, conflict resolution, backup and restore, attachments, and CRDT support. By reducing server load and providing low-latency local queries, RxDB enhances performance and scalability, making it ideal for applications that require real-time updates, offline access, and cross-platform consistency.

​WatermelonDB is a reactive database framework designed to build powerful React and React Native apps that scale from hundreds to tens of thousands of records while remaining fast. It ensures instant app launch regardless of data volume, supports lazy loading to load data only when needed, and offers offline-first capabilities with synchronization to your own backend. It is multiplatform. Optimized for React, it allows easy integration of data into components and is framework-agnostic, enabling the use of its JavaScript API with other UI frameworks. Built on a robust SQLite foundation, WatermelonDB provides static typing with Flow or TypeScript and optional reactivity through an RxJS API. WatermelonDB addresses performance issues in complex applications by loading nothing until requested and performing all querying directly on SQLite on a separate native thread, ensuring most queries resolve instantly.