Obsidian

Markdown knowledge base with linked notes and local-first plugins.

Overview

Obsidian is a free note-taking and knowledge management application designed for personal use, with a focus on privacy and ownership. Your notes are stored locally on your device as plain text Markdown files, ensuring you maintain complete control over your data. The app offers powerful features like bidirectional linking, graph visualization, and an extensible plugin system to tailor the experience to your workflow.

Beyond the core app, Obsidian provides optional paid services: Sync enables secure cross-device synchronization with end-to-end encryption, while Publish lets you turn your notes into a public web presence. The company also offers Catalyst and Commercial licenses to support independent development.

Key features

Bidirectional linking between notes
Interactive graph visualization
Canvas for brainstorming and diagramming
Thousands of community plugins
Customizable themes
End-to-end encrypted sync
Local storage with open file formats
Version history tracking
Collaborative shared vaults
Web publishing with custom domains

Pros

Completely free core app with no limits
Full data ownership with local storage
Open file formats prevent vendor lock-in
Highly extensible via plugins and API
Strong privacy—no telemetry or data collection
Works offline
Flexible for any workflow or use case

Cons

Sync and Publish require paid subscriptions
Steeper learning curve for new users
Requires manual setup and configuration
Mobile apps may have feature parity gaps
Community-driven plugin ecosystem can be inconsistent

Use this if

You want a private, offline-first note-taking app with powerful linking and visualization features, and you value data ownership and customization.

Skip this if

You need real-time collaboration out of the box, prefer cloud-first solutions, or want a simpler app with minimal configuration.

Best for

Personal knowledge managementBuilding digital gardensOrganizing research and ideasCreating interconnected notesTeams collaborating on shared vaultsPublishing documentation or wikis