Obsidian
Local-first Markdown notes and knowledge base
obsidian.md- Price
- FreemiumThe core app is free for personal and commercial use; optional Obsidian Sync runs roughly $4-8/month and Publish about $8-10/month, with a commercial license available for larger organizations.
- Works on
- Windows, macOS, Linux, Android, iOS
- Based in
- Canada
- Source code
- Closed source
- Encryption
- End-to-end encrypted
Obsidian stores your notes as plain Markdown files in a local folder you control so your data never has to touch a server and stays readable in any text editor. That local-first design is its biggest privacy strength: nothing is uploaded unless you choose to enable a paid sync or publishing service. The catch is that the desktop and mobile apps, along with the Sync service, are closed source so you are trusting Dynalist Inc. rather than an auditable codebase, though the company publishes independent audits: Cure53 tested the apps in 2023 and 2024 and the Sync service in 2024, and Trail of Bits audited Sync in 2025. End-to-end encryption is available but only through the paid Obsidian Sync add-on; the local files themselves sit unencrypted on disk. It is an excellent, offline-capable notes tool, just not a fully open or encrypted-by-default one.
Strengths
- Notes are stored as local plain-text Markdown you fully own and can back up or sync however you like
- Works entirely offline with no account required for the core app
- Optional Obsidian Sync offers end-to-end encrypted syncing across devices
- Huge plugin and theme ecosystem for extending the app
Considerations
- The apps and Sync service are closed source, so only commissioned audits (by Cure53 and Trail of Bits) have reviewed the code
- End-to-end encryption is locked behind the paid Sync subscription
- Local note files are stored unencrypted on disk by default
