Obsidian stores your notes as plain Markdown files in a folder you own, links them into a knowledge graph, and extends through 1,500+ community plugins — built for personal knowledge management over decades. OneNote stores your notes on OneDrive in Microsoft's format, gives you a free-form canvas with native handwriting on tablets, and ships free with any Microsoft account. Obsidian wins for data ownership and networked thought. OneNote wins for handwriting, free tier breadth, and anyone inside Microsoft 365.
| Feature | O Obsidian | O OneNote |
|---|---|---|
| Storage model | Local Markdown files (.md) | OneDrive cloud (with local cache) |
| Data ownership | Absolute — files are yours | Files live on Microsoft's servers |
| Knowledge graph view | Built-in, interactive | No graph visualization |
| Editor model | Markdown source / live preview | Free-form canvas, place anything anywhere |
| Handwriting / stylus | Plugin required, limited | Native, excellent on Surface and iPad |
| Free plan (personal) | Free forever, all features | Free with Microsoft account |
| Plugins / extensions | 1,500+ community plugins | Limited add-ons |
| Search | Fast, file-system speed | Fast, includes OCR on images and ink |
| Sync | Your choice (iCloud, Dropbox, Sync $5/mo, Git, Syncthing) | OneDrive (automatic) |
| Cross-platform | Mac, Windows, Linux, iOS, Android | Web, Mac, Windows, iOS, Android |
| Offline support | Total (files are local) | Strong (full notebooks cached) |
| Team collaboration | Not real-time (Git, shared folder) | Native via OneDrive / SharePoint |
Obsidian's defining design choice is that your notes are plain Markdown files in a folder of your choosing.
Each note is a `.md` text file that any other app can read. If Obsidian shuts down tomorrow, your knowledge base survives as readable text. You can edit notes in any text editor, sync via any service, and migrate to any other Markdown tool. This is total data ownership.
OneNote stores notes in Microsoft's proprietary format on OneDrive servers. You can export to PDF or Word but the editable structure (free-form layouts, embedded ink, audio) loses fidelity. Microsoft is a stable company and OneNote isn't going anywhere soon, but if data sovereignty matters — for regulated industries, privacy-conscious users, or long-horizon archive — Obsidian's local-file model is a different category of guarantee.
Obsidian's signature feature is the local knowledge graph.
Every `[[wikilink]]` between notes becomes an edge in a force-directed graph view you can zoom around. Backlinks panels show every note that references the current page. Unlinked-mention detection surfaces implicit connections. This is the toolkit for personal knowledge management (PKM), Zettelkasten methods, and any approach where the relationships between ideas matter as much as the ideas themselves.
OneNote has no graph visualization. Pages live inside Sections inside Notebooks — a strict hierarchy. You can hyperlink between pages manually but there's no automatic link-graph view and no backlinks panel. For users who think hierarchically (subject → topic → page), OneNote's structure works. For users who think relationally (concept → connection → emergence), Obsidian is in a different league.
OneNote owns this category.
On a Microsoft Surface with Surface Pen, on an iPad with Apple Pencil, or on Android with a supported stylus, OneNote's handwriting is pressure-sensitive, palm-rejected, and feels close to paper. You can mix typed and handwritten notes on the same page, drop images anywhere, and let OCR search find handwritten words later. For tablet-first note-takers, OneNote is one of the strongest free tools available.
Obsidian's handwriting support is plugin-based — Excalidraw, Excalibrain, and a few drawing plugins let you sketch inside your vault, but the experience is desktop-first and clunky on tablets. If pen-on-screen is central to your workflow, OneNote (or a dedicated handwriting app like GoodNotes for iPad) is the right tool; Obsidian + a separate handwriting app paired through file references is the typical hybrid pattern.
Both apps are free for personal use, but the economics differ.
Obsidian is free forever on every platform — graph view, plugins, themes, all included. Optional add-ons are Sync at $5/mo (or use iCloud / Dropbox / Syncthing / Git for free), Publish at $10/mo, and a Commercial license at $50/user/year for using Obsidian at work.
OneNote is free with any Microsoft account. If you already pay $9.99/mo for Microsoft 365 Personal (mainly for OneDrive 1TB + Word + Excel + PowerPoint), OneNote is bundled — the marginal cost of using OneNote is zero. There's no Commercial license fee for business use, just whatever you pay for Microsoft 365 Business.
For pure personal note-taking, both are effectively free. For teams: Obsidian Commercial ($50/user/yr ≈ $4/user/mo) is significantly cheaper than Microsoft 365 Business Standard ($12.50/user/mo) — but you're comparing apples and oranges, because Microsoft 365 includes Word / Excel / Teams / SharePoint that Obsidian doesn't try to replace.
OneNote's sync is automatic and reliable through OneDrive.
Every device gets a local cache so opening OneNote offline shows everything instantly. Edits queue and merge cleanly when you come back online. Mobile apps on iPad, iPhone, and Android are full-featured for capture and review.
Obsidian's sync is your choice — and that flexibility is both a feature and a hassle. Obsidian Sync at $5/mo is the convenient option (end-to-end encrypted, version history, fast). Free alternatives include iCloud (works but occasionally hiccups on mobile), Dropbox, Syncthing (advanced), and Git (for power users). The mobile app is functional but constrained by file-system access on iOS and Android — editing complex Markdown with custom plugins on a phone is harder than on a desktop. If hands-off cross-device sync is a hard requirement, OneNote wins on day one. If you're willing to set up sync once, Obsidian's flexibility lets you avoid lock-in entirely.
OneNote inherits Microsoft's collaboration model.
Drop a notebook in a SharePoint site or shared OneDrive folder and your team has near-real-time co-editing access. For schools, corporations, and any org already running Microsoft 365, OneNote slots into existing collaboration infrastructure with zero setup.
Obsidian is single-user by default. Teams using Obsidian typically share a Git repository of Markdown files — works for async knowledge sharing but not for live co-editing. The Obsidian Sync subscription is also single-user (no team plan). If real-time team collaboration matters, OneNote is built for it and Obsidian isn't — choose accordingly. Many PKM enthusiasts use Obsidian for personal knowledge and a separate tool (Notion, AFFiNE, Confluence) for team work.
Obsidian gives you Markdown ownership and a knowledge graph — best in class for personal PKM but no real-time collaboration and weak on free-form layouts. OneNote gives you a free-form canvas with handwriting and team sharing through Microsoft 365 — but your data lives on Microsoft's servers and there's no link graph. AFFiNE is an open-source workspace that combines block-based docs, an infinite whiteboard (with handwriting), and a relational database, all on local-first storage. You own your data the way Obsidian users do, but you also get team collaboration the way OneNote users do, plus a whiteboard surface neither alone provides. Source on GitHub — MIT-licensed editor, free for self-hosted personal use, paid for managed cloud.