Obsidian
By Obsidian
Obsidian is a local-first note-taking application that stores notes as plain Markdown files and lets users link them together into a personal knowledge graph.
Definition
Obsidian is a local-first note-taking application that stores notes as plain Markdown files and lets users link them together into a personal knowledge graph.
Overview
Obsidian's central idea is ownership: every note is a plain-text `.md` file saved directly on the user's device inside a folder called a "vault," with no proprietary format and no requirement to use the cloud. This makes vaults portable, easy to back up, and readable by any Markdown editor even if Obsidian itself disappears. The app's signature feature is bidirectional linking — typing `[[Note Name]]` creates a link to another note, and Obsidian automatically tracks the reverse connection so users can see which notes reference the current one. A built-in graph view visualizes these links as a network, which is popular for methods like Zettelkasten and "second brain" note-taking. Because the vault is just files on disk, Obsidian supports an extensive plugin ecosystem — community plugins add features like spaced-repetition flashcards, canvas-style visual boards, task management, and integrations with tools such as Excalidraw for embedded sketches. Obsidian is free for personal use, with paid add-ons for official Sync (end-to-end encrypted cloud sync across devices) and Publish (turning a vault into a public website). It is widely used by researchers, writers, developers, and students who want long-term control over their notes rather than being locked into a single company's format, in contrast to more all-in-one, cloud-hosted tools like Notion or Coda.
Key Features
- Notes stored as local Markdown files rather than a proprietary database
- Bidirectional `[[wikilink]]` linking between notes with automatic backlinks
- Interactive graph view showing how notes connect to one another
- Large community plugin and theme ecosystem for customizing functionality
- Optional end-to-end encrypted Sync and a Publish feature for public vaults
- Canvas mode for arranging notes, images, and cards on an infinite board
- Works fully offline since notes live on the device, not a server
- Daily notes, templates, and tagging for structured personal knowledge management