Joplin is a privacy-focused, open-source note-taking and task management application designed for users who want full control over their data. It’s ideal for students, researchers, journalists, and professionals who need to capture, organize, and sync notes across desktop and mobile platforms without relying on proprietary cloud services. Joplin solves the problem of vendor lock-in by storing notes in open Markdown format and offering end-to-end encrypted synchronization.
Built with Electron for desktop and React Native for mobile, Joplin supports multiple sync backends including Nextcloud, Dropbox, OneDrive, WebDAV, and its own Joplin Cloud service. Notes are stored as plain Markdown files with embedded resources, and the app includes a powerful full-text search engine, plugin system, and a browser web clipper for saving web content. The entire ecosystem is designed for transparency, portability, and user sovereignty.
What You Get
- End-to-End Encryption (E2EE) - All synced notes are encrypted client-side using AES-256, ensuring only the user can decrypt them—no cloud provider, including Joplin Cloud, can access note content.
- Markdown-based Notes - Notes are stored as plain Markdown files with support for rich formatting, code blocks, task lists, and embedded media, making them portable and editable in any text editor.
- Evernote Import - Full import of Evernote ENEX files including formatted text, images, attachments, geolocation, and metadata, converted to Markdown with preserved structure.
- Web Clipper Extension - Browser extensions for Chrome and Firefox to save entire web pages, screenshots, or selected text as notes with automatic metadata and resource extraction.
- Multi-Platform Sync - Sync notes across Windows, macOS, Linux, Android, iOS, and terminal via Dropbox, OneDrive, Nextcloud, WebDAV, or Joplin Cloud with conflict resolution and offline-first support.
- Plugin and Theme System - Extend functionality with custom plugins using the JavaScript Extension API, or apply custom themes to change the UI appearance without modifying source code.
Common Use Cases
- Securing sensitive research notes - A graduate student uses Joplin to store confidential academic research with E2EE sync to their personal Nextcloud server, ensuring compliance with institutional data policies.
- Cross-device journaling with media - A writer captures daily thoughts on their phone with photos and audio clips, then edits and organizes them on their Linux desktop using Markdown and plugins.
- Saving research articles for offline reading - A journalist uses the Chrome Web Clipper to archive news articles and PDFs into Joplin, tagging them by topic and searching later without internet access.
- Team collaboration on shared project notes - A small design team shares a Joplin Cloud notebook to collaboratively document user feedback, with real-time sync and URL publishing for stakeholder review.
Under The Hood
Architecture
- Monorepo structure with clearly separated packages for desktop, CLI, mobile, server, and transcription, each maintaining isolated concerns and dependencies
- Service-layer design with dependency injection via container-based registration, cleanly separating data access, business logic, and UI concerns
- Event-driven communication through a centralized EventTarget system that decouples UI components from data layer updates
- Plugin system with extensible interfaces that enable third-party extensions without modifying core code, adhering to the Open/Closed Principle
- REST API implementation with explicit route handlers and model serialization, supporting synchronized data flow across client and server
- TypeScript used extensively with generated database types and strict type guards to ensure type safety from storage to user interface
Tech Stack
- Node.js with Yarn workspaces managing a multi-package monorepo, enabling shared logic across platforms
- Electron and React power the desktop client, while CLI tools leverage the same core packages for consistency
- PostgreSQL serves as the primary database, orchestrated via Docker Compose for multi-container deployments
- Jest, ESLint with custom configurations, and Husky pre-commit hooks enforce testing, code quality, and style standards
- Server-side API built with Express-like patterns and Dockerized for production-grade deployment with security hardening
- CI/CD pipelines via GitHub Actions, Crowdin for localization, and Lerna-style versioning streamline releases across packages
Code Quality
- Extensive test coverage spanning CLI integration, model operations, and plugin APIs with robust assertions on state and side effects
- Strong type safety enforced through TypeScript interfaces and guards, particularly in plugin and user data utilities
- Consistent naming conventions and domain-specific terminology across models, services, and tests
- Robust error handling in CLI commands with detailed output and exit code validation, though custom error classes are not utilized
- Modular design with clear boundaries between core models, database abstractions, and plugin systems, enabling isolated testing and extensibility
- Comprehensive tooling with Webpack and TypeScript for builds, and plugin scaffolding that ensures runtime stability and dependency bundling
What Makes It Unique
- Native end-to-end encryption with client-side key management ensures privacy without dependency on third-party cloud encryption
- Unified sync engine built from scratch to support multiple backends with intelligent conflict resolution and versioned item tracking
- Decoupled architecture that separates core database and synchronization logic from UI frameworks, enabling identical functionality across desktop, mobile, and CLI
- Intelligent migration system that version-controls database schema changes and applies backward-compatible transformations automatically
- Custom SQL parser for lightweight, dependency-free database migrations across all platforms
- Extensible plugin system for note rendering that supports custom editors and export formats while preserving Markdown and HTML compatibility