Obsidian

What it does

Obsidian is a local-first notes app that stores everything as plain markdown files rather than in a proprietary cloud format, built around bidirectional links and a visual graph of connected notes. Unlike the other tools in this category, it ships with no AI features at all — every AI capability comes from optional, community-maintained plugins. Smart Connections adds local, offline semantic search that surfaces related notes automatically using an on-device embedding model, while Copilot for Obsidian adds a chat panel that can answer questions across a vault or generate and rewrite text, typically using your own API key from a provider like OpenAI or Anthropic.

This plugin-based approach is Obsidian’s main trade-off: there’s more setup than an AI-native app that works immediately, and chat-based AI usually carries its own separate API cost. In exchange, users get strong data ownership (their notes are just files on their device), a free core app, and the ability to combine exactly the plugins — AI and otherwise — that fit their workflow, rather than accepting one vendor’s fixed feature set.

Ideal users

• People who want full control over their notes as plain markdown files stored locally, not locked into a proprietary cloud format
• Privacy-conscious users who want AI features (like semantic search) that can run entirely on-device without an API key
• Power users comfortable installing and configuring plugins to assemble exactly the feature set they want

Who should avoid it

• You want AI features working out of the box with no setup — Obsidian ships with no AI at all until you install and configure plugins
• You want a single vendor to support the whole experience — Obsidian's AI capability depends on third-party, community-maintained plugins
• You want built-in real-time collaboration — Obsidian is built primarily around individual, local-first note vaults
• You don't want to manage your own API key — chat-based plugins like Copilot for Obsidian typically require your own OpenAI, Anthropic, or other provider key

Key features

• Local-first storage — notes are plain markdown files on your device, not locked in a proprietary format
• Smart Connections plugin: local-embedding semantic search that surfaces related notes automatically, with no API key required
• Copilot for Obsidian plugin: a chat panel that answers questions over your vault using retrieval-augmented generation and can rewrite or generate text inline
• Bidirectional linking and a graph view for networked notes
• Large, active plugin ecosystem covering AI, task management, and publishing

Pricing

Free — Free (core app, including commercial and organizational use)

The core Obsidian app is free for personal use. Smart Connections and Copilot for Obsidian are free, open-source plugins, but Copilot requires your own paid API key from a provider like OpenAI or Anthropic, so real AI cost depends on usage. As of February 2025, Obsidian is also free for commercial and organizational use — the $50/user/year Commercial License is now a voluntary way to support development rather than a requirement. Optional Obsidian Sync ($4/user/month billed annually, or $5 billed monthly) and Obsidian Publish ($8/site/month billed annually, or $10 billed monthly) are paid separately.

Typical workflows

• While drafting a note, Smart Connections surfaces related past notes in a side panel automatically, without the user needing to search or add manual links.
• A user opens the Copilot for Obsidian chat panel to ask a question spanning many notes in their vault, and Copilot retrieves relevant passages before generating an answer.

Integrations

• Large community plugin ecosystem (task management, publishing, calendar, and more)
• Obsidian Sync (paid, official cross-device sync)
• Obsidian Publish (paid, official site publishing)
• Bring-your-own API key for AI plugins (OpenAI, Anthropic, and others)

Privacy & security notes

Because notes are stored as local markdown files, Obsidian itself has no server-side access to your content by default. Smart Connections runs its embedding model locally, so semantic search works fully offline with no data leaving the device. Copilot for Obsidian and similar chat plugins send relevant note content to whichever AI provider's API key you configure, so privacy in that case depends on that provider's own data policy, not Obsidian's.