Obsidian is a powerful knowledge base and note-taking application that works on top of a local folder of plain Markdown files. It uses a unique linking system inspired by Zettelkasten methodology to create an interconnected personal knowledge graph. Obsidian is free for personal use and has become one of the most popular tools for personal knowledge management, PKM enthusiasts, researchers, and writers.

Key Features

• Local Markdown files — All notes are plain Markdown stored in your own local folder
• Bi-directional linking — [[Wiki-style links]] create automatic backlinks and a knowledge graph
• Graph view — Visual interactive graph showing connections between notes
• Plugin ecosystem — Hundreds of community plugins extending functionality
• Canvas — Infinite whiteboard for spatial organisation of notes and media
• Obsidian Sync and Publish — Optional paid services for sync across devices and publishing to web
• Command palette — Quick access to any action via Ctrl+P
• Custom themes and CSS — Fully customisable appearance with community themes

Why Use It

Obsidian is unmatched in its balance of simplicity and power. The plain Markdown foundation ensures your notes are never locked in a proprietary format, while the bi-directional linking and graph view enable a level of interconnected thinking that linear note-taking apps cannot match.

Use Cases

• Personal knowledge management — Build a lasting personal knowledge base using Zettelkasten methods
• Research organisation — Link papers, ideas, and notes into a connected research graph
• Project management — Track projects, tasks, and decisions with linked notes
• Journaling and daily notes — Maintain daily journals with automatic backlinking

Platform

Windows, macOS, Linux, Android, iOS

Licence

Proprietary (free for personal use, source-available core)

Website

obsidian.md