Nodum vs Microsoft OneNote
A OneNote alternative for text-first, linked note-taking
Nodum is an open-source alternative to Microsoft OneNote for people whose notes are mostly text. OneNote is a freeform notebook canvas built around handwriting and mixed media inside the Microsoft ecosystem. Nodum stores plain markdown files, links them with wikilinks, generates backlinks automatically, and is MIT licensed and self-hostable.
What Microsoft OneNote is
OneNote is Microsoft's digital notebook: notebooks, sections and pages, with a freeform canvas you can type or draw anywhere on. It is free with a Microsoft account, syncs through OneDrive, and is excellent with a stylus. It is not markdown, has no wikilinks or backlinks, and its export options are limited.
Side by side
| Property | Microsoft OneNote | Nodum |
|---|---|---|
| Licence | Proprietary, closed source | MIT — the whole stack, frontend and backend |
| Hosting | Microsoft 365 / OneDrive | Hosted at nodum.md, or self-hosted with one Docker Compose command |
| Your notes are | A proprietary notebook format synced through OneDrive | Plain markdown files, exported as a folder-true zip whenever you ask |
| Linking | Internal page links; no wikilink syntax, no backlinks | [[wikilinks]], [[path/Note]], [[Note|alias]], ![[embeds]] — Obsidian syntax |
| Graph | No graph view | Global and local force-directed graph, GPU-rendered on WebGL2 |
| Pricing model | Free with a Microsoft account; storage counts against OneDrive quota | Free and open source; self-host at your own infrastructure cost |
| Platforms | Windows, macOS, browser, iOS, Android | Any modern browser, desktop and mobile; installable as a PWA |
| Getting out | PDF, or the .one notebook format — no clean markdown path | Vault zip of .md files, plus a REST API and an MCP server |
Where each one actually wins
The left-hand column is the honest part. If none of it applies to you, the switch is probably worth making; if several do, it probably is not.
What Microsoft OneNote does better
- Handwriting and stylus input, which Nodum does not attempt at all.
- The freeform canvas: put anything anywhere on the page.
- Deep integration with Outlook, Teams and the rest of Microsoft 365.
- Free with an account most workplaces already have.
What Nodum does better
- Plain markdown files instead of a proprietary notebook format with no real export.
- Wikilinks, backlinks and a knowledge graph.
- Open source and self-hostable — no Microsoft account, no OneDrive quota.
- A real markdown editor with code blocks, KaTeX maths and Mermaid diagrams.
So — switch, or stay?
Switch to Nodum if…
- Your notes are text and you have hit OneNote's lack of linking.
- You want out of the Microsoft account requirement.
- You want an export that is readable without Microsoft software.
Stay on Microsoft OneNote if…
- You write by hand on a tablet.
- Your team runs on Microsoft 365 and shared notebooks are part of the workflow.
Microsoft OneNote and Nodum: common questions
Is there an open-source alternative to OneNote?
Yes. For text-first notes, Nodum is MIT licensed, stores plain markdown, and adds wikilinks, backlinks and a knowledge graph. Joplin is the closer match if you want OneNote's notebooks-and-tags structure specifically. Neither replaces OneNote's handwriting and freeform canvas.
Can I export OneNote notes to markdown?
Not directly. OneNote exports to PDF or its own .one format, so most people convert with a script or a third-party tool, or copy pages out section by section. Once you have markdown, zip the folder and import it into a Nodum vault.
Before you move anything
Whatever you decide, run this once. It takes ten minutes and it is the difference between a migration and an incident.
- Export from Microsoft OneNote first, and keep that export somewhere safe.
- Import a copy into a throwaway Nodum vault, not your main one.
- Open the graph and look for ghost nodes — those are links that did not resolve.
- Export the Nodum vault and diff it against what you put in.
- Only then delete anything.
Other comparisons
Every comparison is on the alternatives index, and the glossary defines the vocabulary these pages use.
Bring your Microsoft OneNote notes with you.
Import a zip, look at the graph, export it again. Nothing about it is one-way.