Obsidian is a desktop and mobile application for note-taking built on plain Markdown files. It stores notes locally (no cloud, no account required) and visualizes the network of connections between them as a graph. It has become the dominant tool for personal knowledge bases and digital gardens.
What makes it different
Several design choices distinguish Obsidian from competitors like Notion or Roam:
- Local-first — your notes are
.mdfiles in a folder you control. No vendor lock-in. Works offline forever. - Markdown native — no proprietary format. Files open in any text editor.
- Graph view — every link is tracked bidirectionally. The graph view shows the topology of your thinking.
- Plugins — community-built extensions for backlinks, Dataview queries, canvas, daily notes, slide decks, and hundreds of others.
- Cross-platform — Windows, macOS, Linux, iOS, Android.
Core concepts
- Vault — a folder containing your notes. The unit of organization.
- Wikilinks —
[[page-name]]syntax creates a link to another note without knowing its path. Clicking creates the note if it doesn’t exist. - Backlinks — every page shows all pages that link to it, not just from it. This is the killer feature for a knowledge base.
- Tags —
#tag-nameinline ortags: [tag1, tag2]in frontmatter. Filterable, hierarchical. - Graph view — force-directed visualization of all notes and links.
- Daily notes — auto-created journal entries for each day.
- Canvas — freeform spatial canvas for visual thinking.
Obsidian Publish
For users who want to make a vault public, Obsidian offers a paid service called Obsidian Publish. It renders a vault as a website with the same graph view, backlinks, and navigation as the desktop app.
This site is a replacement for Obsidian Publish for users who:
- Don’t want the subscription.
- Want full control over the design.
- Need better performance for large vaults.
- Want to publish via Cloudflare Pages or GitHub Pages.
- Need to integrate the KB with an AI agent workflow.
Obsidian + LLM workflows
The natural pairing of Obsidian + LLMs has produced several patterns:
- Copilot plugin — chat with an LLM about your vault directly in Obsidian.
- Smart Connections — semantic search over the vault using embeddings.
- Karpathy LLM Wiki pattern — Obsidian as the IDE, an LLM agent as the maintainer, markdown as the storage. See this site’s README for the full pattern.
- Custom scripts — many users run scripts (Python, Node) to extract and re-ingest sources into their vault.
Limitations
- Mobile is limited — the iOS and Android apps are less full-featured than desktop.
- No real-time collaboration — multi-user editing requires external tools.
- Plugins are sandboxed — limited compared to full IDEs like VS Code.
- Large vaults slow down — the graph view becomes unusable past ~10K notes.
See also
- Knowledge Base — what Obsidian is optimized for
- Digital Garden — Obsidian’s most common publishing target
- Astro — alternative for publishing a knowledge base as a website