PouchDB vs RxDB

PouchDB is a free, open-source JavaScript database for browser and Node.js applications. It keeps documents locally so applications can continue working offline, then synchronizes data bidirectionally with CouchDB-compatible servers when online. The same API is used in browsers and Node.js. Browser storage uses IndexedDB by default, while the documented Node.js adapter uses Node’s native SQLite module with Node.js versions later than 22.5.0. Supported server integrations include CouchDB 1.x, 2.x, and 3.x, Cloudant, and PouchDB Server. PouchDB is framework-agnostic and can work with Angular, React, Ember, Backbone, or another framework. It also runs with Cordova/PhoneGap, NW.js, Electron, and Chrome apps. Documents must be serializable as JSON, and attachments can be base64-encoded strings or Blob objects. Direct synchronization with a non-CouchDB database requires a backend that speaks the CouchDB replication protocol. Platforms listed are Android, API, extension, iOS, self-hosted, web, and Windows. The project lists GitHub Discussions, Slack, and Stack Overflow for discussion.

RxDB is a NoSQL database for JavaScript that runs inside an application and keeps data locally on the client. It supports offline operation, including applications that run entirely without a backend. When synchronization is needed, its Sync Engine connects to backends including RxServer, GraphQL, Firebase, Supabase, MongoDB, NATS, HTTP, CouchDB, WebRTC, Appwrite, Google Drive, and Microsoft OneDrive. Observable queries update as stored data changes. RxDB runs in browsers, mobile apps, desktop applications, and servers, with storage options including LocalStorage, IndexedDB, OPFS, SQLite, Node.js Filesystem, Expo Filesystem, MongoDB, and FoundationDB, among others. Collections use JSON Schema with validation and migration support. An encryption plugin protects locally stored documents with a password in browsers, React Native, and Node.js. The free tier is under Apache 2.0 and allows up to 13 open collections in parallel. Free users get community support through GitHub and Discord; Enterprise includes an SLA with a 24-hour first response. Pro costs $99 a month billed annually, and Pro Plus costs $239 a month billed annually.