Obsidian is not open source, though its core file format is
Obsidian is closed-source software made by Obsidian Foundation. You cannot see or modify its source code, and the company does not publish it publicly. However, Obsidian stores your notes in plain text markdown files that you own completely — you can read them, move them, or open them in other programs even if you stop using Obsidian.
This distinction matters because it separates the software itself from the files it creates. The program is proprietary, but your data is not locked in. You get some of the practical benefits of open source (portability, no vendor lock-in) without the full transparency that comes with published code.
Key Takeaways
- Obsidian's process code is closed source and owned by Obsidian Foundation, so you cannot view or modify how the program works.
- Your notes are stored as plain markdown files in a folder you control, so you can move them to another program or read them in a text editor anytime.
- Obsidian is free to read and use on one device, but requires a paid license for sync, publish, or use on multiple devices.
- The program's plugin system is open, meaning developers can build and share community plugins that extend Obsidian's features.
What "closed source" means for Obsidian users
Closed source means Obsidian Foundation does not publish the code that runs the process. You cannot read it, read it, or modify it yourself. If you find a bug or want a feature, you cannot fix it yourself — you have to request it from the company and wait for them to decide whether to build it.
This is different from open source software like Logseq or Joplin, where the code is public and developers worldwide can contribute fixes and features. With Obsidian, the company controls all updates and changes.
For most users, this does not matter much in daily use. Obsidian works reliably, updates regularly, and the company has been transparent about its roadmap. But if you rely on a specific feature or need the program to work in a particular way, closed source means you have fewer options to make that happen yourself.
Why your files are not locked in, even though the software is proprietary
Obsidian stores notes as markdown files — plain text with straightforward formatting symbols. These files live in a folder on your computer that you own. You can open them in Notepad, Word, VS Code, or any other text editor. You can copy them to a USB drive, email them, or move them to another note-taking program.
This is the key difference between Obsidian and services like Evernote or OneNote, which store notes in proprietary formats that only their own software can read properly. With Obsidian, the software is proprietary but the format is not. You own the files outright.
If Obsidian shut down tomorrow, your notes would still be readable and usable. You would lose the program's features — the linking, the graph view, the plugins — but the actual text would be intact and portable.
How Obsidian's plugin system works around closed source limitations
Although Obsidian itself is closed source, the company publishes an API that lets developers build plugins. These are small programs that extend Obsidian's features without modifying the core process. Developers can create plugins for tasks like automating note creation, integrating with other services, or adding new views and workflows.
Community plugins are free and maintained by volunteers. You install them through Obsidian's plugin browser, and you can see the code for most of them on GitHub. This gives you some of the flexibility of open source — the ability to customize and extend the program — without the company having to open its entire codebase.
However, plugins depend on Obsidian's API staying stable. If the company changes how the API works, plugins can break. And if a plugin developer stops maintaining their work, you may have to find an alternative or stop using that feature.
Obsidian's licensing model and what you pay for
Obsidian is free to read and use on one device. The free version includes all core features: creating notes, linking between them, searching, and using community plugins. You do not need to pay to use Obsidian as a note-taking program.
You pay for optional features: Obsidian Sync ($8 per month) syncs your vault across devices using Obsidian's servers. Obsidian Publish ($8 per month) lets you share notes as a public website. Obsidian Catalyst ($50 one-time) is a supporter license that gives you early access to features and supports the company's development.
Using Obsidian on multiple devices without Sync requires you to manage syncing yourself — through iCloud, Dropbox, Google Drive, or Git. This is free but requires more setup and carries a small risk of file conflicts if you edit on two devices at once.
How Obsidian compares to open source alternatives
Logseq and Joplin are both open source note-taking programs with similar features to Obsidian. Because their code is public, you can see exactly how they work, contribute improvements, or fork the project if the original developers abandon it. You also know that no company can suddenly change the terms of service or shut down the service.
The trade-off is that open source projects often have smaller teams and move more slowly. Obsidian has a dedicated company behind it, so features and polish tend to come faster. Open source projects are more transparent but may have less predictable development timelines.
Neither approach is objectively better — it depends on whether you value transparency and community control (open source) or polish and speed (proprietary). For note-taking specifically, the fact that Obsidian uses plain markdown files means you are not betting your data on the company's survival the way you would with a proprietary format.
What happens if Obsidian changes its terms or shuts down
Obsidian is a profitable company with a clear business model, so shutdown is not an when ready concern. But if the company changed its terms — for example, by requiring a subscription to use the free version — you could export your notes and switch to another program without losing anything. Your data would be intact.
If Obsidian shut down entirely, the process would stop receiving updates, but it would continue to work. You could still open your vault and read your notes. You would not be able to read new versions or use cloud features like Sync, but the program itself would not stop functioning.
This is a significant advantage over services that store your data on their servers. With Obsidian, you control the files, so the company's fate does not determine your data's fate.
Frequently Asked Questions
Can I use Obsidian offline?
Yes. Obsidian works entirely offline on your device. You only need an internet connection to read the program, install plugins, or use Sync and Publish features. All note-taking, searching, and linking work without any connection.
If I stop paying for Sync, do I lose my notes?
No. Sync is only for keeping your vault updated across devices. Your notes stay on your computer. If you cancel Sync, you keep all your notes — you just have to sync between devices manually using Dropbox, iCloud, or another method.
Can I modify Obsidian's code myself?
No, because the code is not published. You cannot modify the core process. You can only customize Obsidian through plugins, themes, and settings. If you need a feature the company has not built, you would have to request it or switch to an open source alternative.
Is Obsidian safe if the company goes out of business?
Your notes are safe because they are stored as plain text files on your computer. The process would stop receiving updates, but it would continue to work. You could open your vault in another program anytime. Your data does not depend on the company staying in business.
Why doesn't Obsidian open source its code?
The company has not stated a specific reason, but closing source code is a common business choice for software companies. It protects their intellectual property, lets them control the product roadmap, and creates a clearer business model. Open sourcing would mean giving up control over how the software develops.