Obsidian is not open source, but the core vault format it uses is
Obsidian is closed-source software made by Obsidian Foundation. You cannot see or modify its source code, and you cannot legally redistribute it. However, the underlying file format — plain text markdown stored in folders on your computer — is completely open and belongs to no one. This means your notes are not locked into Obsidian's ecosystem. You can read and edit them with any text editor, move them to another note-taking app, or process them with your own scripts.
The distinction matters because it affects what you can do with your data and what happens if Obsidian disappears. The software itself is proprietary, but the data format is yours to keep and use however you want.
Key Takeaways
- Obsidian's code is not open source, meaning you cannot see how it works or modify it yourself.
- Your notes are stored as plain markdown files in folders you control, so you are not locked into Obsidian if you want to switch apps.
- Obsidian offers a free version for personal use and paid plans for sync and publishing features.
- If open source software is important to your workflow, alternatives like Logseq and Joplin publish their source code publicly.
What "open source" actually means for note-taking software
Open source means the software's source code is publicly available for anyone to read, modify, and redistribute under a specific license. For note-taking apps, this usually means you can inspect how the app handles your data, fork the code to build your own version, or contribute improvements back to the project.
Obsidian does not do this. The Obsidian Foundation keeps the code private. You download a compiled application and use it under their terms. If you want to know exactly how Obsidian encrypts your sync data or processes your markdown, you cannot read the code to find out — you have to trust the company's documentation.
This is not unusual. Most commercial software works this way. The tradeoff is that closed-source projects can move faster and make business decisions without community consensus, but they also require you to trust the company's judgment about security and privacy.
Why your data stays portable even though Obsidian is closed source
Obsidian stores your notes as plain markdown files in a folder structure you choose on your computer. Markdown is a simple text format that any text editor can read — Notepad, VS Code, Apple Notes, or any other app. This is not a feature Obsidian invented; it is a standard format that has existed for over a decade.
Because of this, you own your notes in a way that matters. If Obsidian shut down tomorrow, your files would still be readable. If you want to switch to Logseq, Joplin, or any other markdown-based app, you can copy your vault folder and open it there. No export process, no conversion, no data loss.
This portability is why many people choose Obsidian despite it being closed source. The closed-source part affects how the software works, but the open format affects what you can do with your data.
How Obsidian makes money and what you pay for
Obsidian is free to download and use for personal note-taking on your computer. The company makes money through two optional paid services: Obsidian Sync (which syncs your vault across devices using Obsidian's servers) and Obsidian Publish (which lets you publish your notes as a website). Both are subscription services you can choose to use or skip.
The free version includes all the core features: creating notes, linking between them, using plugins, and customizing the interface. You do not need to pay anything to use Obsidian as your main note-taking app. The paid services are for people who want cloud sync or public publishing, which require infrastructure that costs money to run.
This model is common among closed-source software. The source code stays private, but the basic software is free, and the company funds itself through optional add-ons.
Open source alternatives if that matters to your workflow
If you want a note-taking app where the source code is publicly available, two popular alternatives are Logseq and Joplin. Both are free, both store notes as markdown, and both publish their code on GitHub where anyone can read it, modify it, or build their own version.
Logseq works similarly to Obsidian — it uses markdown files in folders you control and emphasizes linking and backlinks. Joplin is more traditional but includes built-in sync and encryption. Both have smaller communities than Obsidian, which means fewer plugins and templates, but also means the software is maintained by people who believe in open source principles.
The choice between closed-source Obsidian and open-source alternatives usually comes down to features and community size rather than licensing alone. Obsidian has more plugins, more templates, and a larger user base. The open source apps have transparency and community control. Your notes stay portable either way because they are all markdown.
What you should know about Obsidian's privacy and security
Because Obsidian is closed source, you cannot audit the code yourself to verify how it handles your data. You have to read Obsidian's privacy policy and trust their claims. The company says it does not read your notes, does not sell your data, and does not track you — but you cannot verify this by reading the code.
For local notes stored only on your computer, this matters less. Your data never leaves your device unless you use Obsidian Sync, which encrypts your vault before sending it to Obsidian's servers. The company publishes a security whitepaper explaining how this works, but again, you cannot verify it independently without the source code.
If privacy and transparency are critical to you, an open source alternative lets you read exactly how your data is handled. If you trust Obsidian's documentation and want the larger plugin ecosystem, the closed-source model is not a dealbreaker — your notes are still yours because they are stored as plain markdown.
Frequently Asked Questions
Can I use Obsidian for free forever?
Yes. The core Obsidian app is free for personal use with no time limit. Paid features like Sync and Publish are optional. If you never use those services, you never pay anything.
If Obsidian goes out of business, can I still read my notes?
Yes. Your notes are stored as plain markdown files in folders on your computer. Any text editor can open them. You could also import them into Logseq, Joplin, or any other markdown app without any conversion.
Does closed source mean Obsidian is less secure than open source apps?
Not necessarily. Security depends on how well the software is written and tested, not on whether the code is public. Closed source means you cannot audit the code yourself, but it does not mean the code is less secure. Open source lets you verify security yourself, but only if you have the skills to read and understand the code.
Can I modify Obsidian to add features I want?
You cannot modify Obsidian's core code because it is closed source. However, Obsidian has a plugin system that lets you add features without touching the source code. Thousands of community plugins are available, and you can write your own if you know JavaScript.
Is Obsidian owned by a big company?
No. Obsidian is made by Obsidian Foundation, a small independent company. It is not owned by a larger tech company, which means decisions about the software are made by the team that built it rather than by corporate shareholders.