pouchdb

PouchDB is a pocket-sized database

weekly downloads53K

versionv9.0.0

licenseApache-2.0

categorydatabase

dbcouchdbpouchdb

Overview

PouchDB is a JavaScript NoSQL database that runs in browsers and Node.js environments, implementing the CouchDB API specification. It stores data locally using IndexedDB in browsers or LevelDB in Node.js, providing a consistent API across all platforms through its adapter system. The library automatically selects the optimal storage backend for your environment without requiring configuration changes.

The primary purpose of PouchDB is enabling offline-first applications with reliable bidirectional synchronization to CouchDB-compatible servers. When network connectivity is available, PouchDB can replicate data to remote databases and automatically handle conflicts using revision trees. This makes it particularly valuable for applications that need to function without constant internet connectivity, such as mobile apps, field service tools, or collaborative editing platforms.

PouchDB is maintained as an Apache-2.0 licensed open-source project and sees consistent usage with over 53,000 weekly downloads. The library is used by development teams building progressive web apps, Electron applications, and Node.js services that require local-first data architecture. Version 9.0.0 represents the current stable release with refined adapter selection and consistent core operations across all supported environments.

Developers can use PouchDB as a complete package or install modular components like pouchdb-core with specific adapters to reduce bundle size. The plugin ecosystem extends functionality for map/reduce queries, full-text search, and authentication. PouchDB can also run as a standalone CouchDB-compatible server using pouchdb-server, making it suitable for development environments or lightweight production deployments.

Quick Start

typescript

const PouchDB = require('pouchdb');

const localDB = new PouchDB('todos');
const remoteDB = new PouchDB('http://localhost:5984/todos');

async function example() {
  const todo = {
    _id: new Date().toISOString(),
    text: 'Learn PouchDB',
    completed: false,
    createdAt: Date.now()
  };

  const response = await localDB.put(todo);
  console.log('Created:', response.id, response.rev);

  const doc = await localDB.get(response.id);
  doc.completed = true;
  await localDB.put(doc);

  const allTodos = await localDB.allDocs({
    include_docs: true,
    descending: true
  });
  console.log('Total todos:', allTodos.total_rows);

  const changes = localDB.changes({
    since: 'now',
    live: true,
    include_docs: true
  }).on('change', (change) => {
    console.log('Document changed:', change.id);
  });

  const sync = PouchDB.sync(localDB, remoteDB, {
    live: true,
    retry: true
  }).on('change', (info) => {
    console.log('Synced:', info.direction);
  }).on('error', (err) => {
    console.error('Sync error:', err);
  });

  await localDB.bulkDocs([
    { _id: 'task-1', text: 'Build app', completed: false },
    { _id: 'task-2', text: 'Deploy app', completed: false }
  ]);

  return { sync, changes };
}

example().catch(console.error);

Use Cases

Offline-capable mobile and web applications: Build progressive web apps or hybrid mobile applications that store user data locally and sync when connectivity returns. Users can create, edit, and delete documents while offline, with automatic synchronization and conflict resolution when back online.

Real-time collaborative tools: Implement document editing, task management, or note-taking applications where multiple users work on shared data. PouchDB's changes feed enables live updates across clients, while its replication handles merging concurrent edits through its built-in conflict resolution.

Field service and data collection apps: Deploy applications for technicians, healthcare workers, or researchers who collect data in areas with unreliable connectivity. Data persists locally on devices and syncs to central CouchDB servers when network access is restored.

Cross-platform Electron applications: Build desktop applications with consistent data storage across Windows, macOS, and Linux. PouchDB provides the same API regardless of platform, with automatic adapter selection for optimal performance on each operating system.

Development and testing environments: Use PouchDB as a local CouchDB replacement during development to avoid external dependencies. The pouchdb-server package provides a CouchDB-compatible HTTP API for testing replication logic without deploying actual CouchDB instances.

Pros & Cons

Pros

+Seamless bidirectional synchronization with CouchDB and compatible servers like Cloudant, with automatic conflict resolution using revision trees
+Consistent API across browsers (IndexedDB/WebSQL) and Node.js (LevelDB) through intelligent adapter system, requiring no code changes between environments
+Strong offline-first capabilities with local persistence, allowing applications to function completely without network connectivity
+Comprehensive plugin ecosystem for extending functionality with map/reduce queries, full-text search, authentication, and custom adapters
+Live changes feed enables real-time reactive applications with filtered, continuous updates without polling

Cons

−Large bundle size (~500KB+ for full distribution) compared to simpler storage libraries, though modular builds can reduce this significantly
−Limited query capabilities compared to SQL databases, relying primarily on document IDs and secondary indexes through map/reduce views
−Slower query performance on large datasets compared to native IndexedDB wrappers or SQLite-based solutions, as it prioritizes sync fidelity over speed
−Revision tree storage model can accumulate metadata overhead over time, requiring periodic compaction to maintain performance
−Learning curve for developers unfamiliar with CouchDB's document model, revision handling, and eventual consistency concepts

Alternatives

dexiev4.3.0

A Minimalistic Wrapper for IndexedDB

databaseindexeddbbrowser

990K / week

Comparisons

dexie vs pouchdb

database

Install

bash

npm install pouchdb

bash

pnpm add pouchdb

bash

bun add pouchdb

Overview

Quick Start

typescript

const PouchDB = require('pouchdb');

const localDB = new PouchDB('todos');
const remoteDB = new PouchDB('http://localhost:5984/todos');

async function example() {
  const todo = {
    _id: new Date().toISOString(),
    text: 'Learn PouchDB',
    completed: false,
    createdAt: Date.now()
  };

  const response = await localDB.put(todo);
  console.log('Created:', response.id, response.rev);

  const doc = await localDB.get(response.id);
  doc.completed = true;
  await localDB.put(doc);

  const allTodos = await localDB.allDocs({
    include_docs: true,
    descending: true
  });
  console.log('Total todos:', allTodos.total_rows);

  const changes = localDB.changes({
    since: 'now',
    live: true,
    include_docs: true
  }).on('change', (change) => {
    console.log('Document changed:', change.id);
  });

  const sync = PouchDB.sync(localDB, remoteDB, {
    live: true,
    retry: true
  }).on('change', (info) => {
    console.log('Synced:', info.direction);
  }).on('error', (err) => {
    console.error('Sync error:', err);
  });

  await localDB.bulkDocs([
    { _id: 'task-1', text: 'Build app', completed: false },
    { _id: 'task-2', text: 'Deploy app', completed: false }
  ]);

  return { sync, changes };
}

example().catch(console.error);

Use Cases

Pros & Cons

Pros

+Seamless bidirectional synchronization with CouchDB and compatible servers like Cloudant, with automatic conflict resolution using revision trees
+Consistent API across browsers (IndexedDB/WebSQL) and Node.js (LevelDB) through intelligent adapter system, requiring no code changes between environments
+Strong offline-first capabilities with local persistence, allowing applications to function completely without network connectivity
+Comprehensive plugin ecosystem for extending functionality with map/reduce queries, full-text search, authentication, and custom adapters
+Live changes feed enables real-time reactive applications with filtered, continuous updates without polling

Cons

−Large bundle size (~500KB+ for full distribution) compared to simpler storage libraries, though modular builds can reduce this significantly
−Limited query capabilities compared to SQL databases, relying primarily on document IDs and secondary indexes through map/reduce views
−Slower query performance on large datasets compared to native IndexedDB wrappers or SQLite-based solutions, as it prioritizes sync fidelity over speed
−Revision tree storage model can accumulate metadata overhead over time, requiring periodic compaction to maintain performance
−Learning curve for developers unfamiliar with CouchDB's document model, revision handling, and eventual consistency concepts