An Open-Source Alternative to Notion: Three Candidates Compared

The renewal notice arrives on a Tuesday. You are the team lead, so you open the pricing page and do the multiplication one more time. Notion lists Plus at $10 per member per month and Business at $20. Twelve people, a few contractors, one workspace. The number you get is not catastrophic. It is just a number that grows every time someone joins.

You check the guest option first. Guests are free, but they can only access individual pages, so the contractors who live in three spaces still need seats. That is the moment the search usually starts: "notion open source alternative". This post is for that moment.

What "alternative" actually has to match

An alternative does not have to match Notion's feature page. It has to match your workflows: the meeting notes, the wiki, the database your team actually opens every day. Before you compare candidates, it is worth knowing exactly how portable your current content is, from Notion's own documentation.

Workspace export covers HTML, Markdown, and CSV for databases, plus your uploaded files. That is the good news. The fine print matters more. Notion states plainly that you can't instantly recreate your workspace by reuploading exported content. Download links expire after 7 days, and exports can take up to 30 hours to process. On Enterprise plans, workspace or teamspace owners can disable member exporting entirely. And workspace PDF export is being removed, with rollout through 31 August 2026.

None of this is a complaint. It is documented behavior, and it sets the bar: any candidate you evaluate should export your data in a form you can re-import elsewhere, on your schedule.

Facts below checked against primary sources on September 2, 2026.

A checklist that works for any candidate

Run these five checks before you fall in love with a demo. They apply to any self-hosted tool, not just the three below.

1. License. Read the LICENSE file, not the badge. Monorepos sometimes split licenses by directory, and "core" licenses can hide enterprise-gated features.
2. Deployment model. Find the official install path. Docker Compose, Kubernetes, single binary. Note every dependency it drags in: databases, caches, proxies.
3. Data export. What formats come out, and can a restore get your content back? A backup that only restores one component is not a full exit.
4. Project activity. Check the releases page and issue tracker. Look at dates, not stars. Recent, steady releases beat a big number that stopped moving.
5. Maintenance burden. Who upgrades it, backs it up, and watches it at 2 a.m.? If the answer is "nobody yet", that is your answer.

The proof: three candidates, same five checks

I applied the checklist to three candidates on September 2, 2026. Sources: the AFFiNE repository and self-host docs, the Docmost repository and installation docs, and the SiYuan repository with its releases.

	AFFiNE	Docmost	SiYuan
License	CE described as MIT, but split LICENSE: backend carries a separate license; EE needs a subscription for production	AGPL-3.0 core; enterprise features in ee directories under an enterprise license	AGPL v3; most features free for commercial use, some paid
Deploy	Docker Compose recommended; Postgres only, Redis required; 4 cores, 2 GB RAM minimum	Docker Compose recommended; Postgres 18, Redis 8, APP_SECRET of 32+ characters; claims air-gapped operation	Official Docker image b3log/siyuan on port 6806, workspace bind mount, accessAuthCode required
Data export	Official backup is pg_dump plus blobs and config; database-only restore loses uploaded files	Markdown or HTML ZIP export; Notion ZIP import; Confluence, PDF, DOCX import are Enterprise	Markdown with assets, PDF, Word, HTML; .sy JSON on disk. But Docker hosting cannot export PDF, HTML, or Word
Latest release	v0.27.4, 18 Aug 2026; 72.1k stars, 614 issues	v0.95.0, 3 Jul 2026, security fixes; 21.6k stars, 223 issues	v3.8.2, 30 Aug 2026; 46.1k stars, 79 open issues
Self-host burden	Postgres, Redis, volumes, config; 0.27.4 changed Compose paths and dropped .env, so guides rot fast	Postgres, Redis, WebSockets at the proxy for the realtime editor	Lightest of the three; but auth is a lock-screen access code and it is positioned as personal-first, not a multi-tenant workspace

Notion stays as the context row in your head: whatever you pick, the migration path out of it is the export behavior described above.

Why the usual suspects are missing

You will notice some famous names absent. That is the checklist working, not an oversight.

AppFlowy-Cloud was archived on 1 September 2026. The README calls it legacy and unmaintained, and says production self-hosting is a closed-source commercial fork with a free tier of one user seat. Outline's LICENSE is Business Source License 1.1, which states in its own text that it is not an Open Source license (its change date to Apache-2.0 is 2030-09-01). Wiki.js 3.0.0-beta.537 is explicitly marked not for production use; v2.5.314 is the production latest.

One action you can take today

Do not migrate anything yet. Pick one real workflow, something small and loud, like the weekly meeting-notes database. Pilot one candidate against exactly that for one week. You will learn more about export paths, auth, and upgrade pain in seven days of real use than in any feature table.

When you are done, take the checklist back to your shortlist. More field notes live at /open-source, and the rest of the series is on the blog.

Reports come from the worker. Verdicts come from a judge. This post is the worker's report: every cell above links to a primary source you can open yourself.

Caveats

• Feature tables rot fast. The checked-at date of September 2, 2026 bounds every claim here, including versions and star counts. Re-verify before you rely on any of them.
• License nuance: Docmost and SiYuan are AGPL-3.0, which carries network-copyleft implications a company should run past counsel. This is not legal advice. AFFiNE CE is described as MIT, but the backend carries a separate license.
• No candidate here is "the winner". Fit depends on your constraints: team size, compliance, who is on call.

Disclosures

• First-party interest: ranex.dev is my site, and this series covers the open-source ecosystem I work in.
• AI assistance was used in the research and drafting of this post.
• Human review is required. This post is scheduled for review before publication.

FAQ

Is AFFiNE really MIT licensed?

Mostly, for the Community Edition. AFFiNE CE is described as MIT and free for self-hosting, but the repository LICENSE is split: packages/backend and packages/common/native carry a separate license, and the EE server code requires a valid Enterprise Edition subscription for production use. Read the LICENSE files yourself before committing.

Which candidate is closest to Notion?

None is a full replacement. Docmost is the most team-oriented of the three, but its Bases feature (Table and Kanban) is Enterprise-only as of v0.95.0. AFFiNE's official backup procedure is a Postgres pg_dump plus blobs rather than a document export. SiYuan describes itself as a privacy-first personal knowledge system, and its official Docker hosting cannot export PDF, HTML, or Word.

What about AppFlowy?

The AppFlowy-Cloud repository was archived on 1 September 2026. Its README calls it legacy and unmaintained, and says production self-hosting is now a closed-source commercial fork with a free tier of one user seat. That is why it is not in the table.

Will my Notion content migrate cleanly?

Partly. Non-database pages export as Markdown and full-page databases as CSV, with callouts becoming HTML. But you cannot export all database views at once, Form views cannot be exported, and Notion states you cannot instantly recreate a workspace by re-uploading exported content. Databases, views, and permissions will not round-trip.