Open-source alternatives to Notion: 7 note-taking and knowledge base tools compared

Where these seven sit on the Notion shape

Notion is a hosted workspace that combines documents, databases, wikis and project boards in one editor, shared across a team, and the reasons people look for an alternative are structural: everything lives on Notion's servers and works only online, per-member pricing grows with the team, and export is limited to Markdown, CSV, HTML or PDF with database relations that do not survive it. That last point matters more than it first appears, because the database is the part of Notion that people actually build on, and no file format carries a relation graph. Wherever you land, your views get rebuilt.

With that in mind the seven split into three shapes, and picking the wrong shape is the expensive mistake.

The Notion-shaped workspaces are AppFlowy and, at a distance, AFFiNE. AppFlowy is the closest: a Flutter and Rust app for projects, wikis and teams, shipping desktop builds for macOS, Windows and Linux plus apps for iOS and Android, which is the combination a team that has been using Notion on phones and laptops is most likely to miss otherwise. AFFiNE is a different proposition with the same goal: its README describes docs, canvas and tables as hyper-merged, so any building block, from rich text to sticky notes to embedded pages, multi-view databases, linked pages, shapes and slides, can sit on an edgeless canvas, and it is local-first with real-time sync across web and cross-platform clients.

The team wikis are Outline and Docmost. Outline is a React frontend on a Node.js backend aimed at realtime collaborative documents, Markdown compatible, and its README is unusually direct that the repository is the source of the hosted product. Docmost is a wiki and documentation application with realtime collaboration, diagrams through Draw.io, Excalidraw and Mermaid, spaces, permissions management, groups, comments, page history, search and file attachments. Both are narrower than Notion: they give you documents and structure, not the database canvas.

The personal tools are SiYuan, Logseq and Anytype, and this is where expectations get misaligned most often. SiYuan is a personal knowledge management system storing notes as blocks with fine-grained block-level references and Markdown WYSIWYG, running on desktop, mobile or Docker behind a Go kernel with a REST API. Logseq is an outliner that keeps notes as Markdown or Org-mode files you own, with a database version that moves the same outliner onto SQLite graphs and is still beta. Anytype describes itself as a personal knowledge base with pages, tasks, wikis and journals and custom Types you define, offline-first with zero-knowledge encryption and peer-to-peer sync, shipped as an Electron and TypeScript client around a separate Go engine. All three are excellent for a person, and none of them is a team workspace in the sense Notion is.

What is not on this list, and why, is worth a sentence. Classic wiki engines, collaborative office suites and other hosted products are absent on purpose: this comparison covers seven open-source candidates, and each of those other categories arrives with a different data model, an article per page or an office document rather than a block, which turns a migration into a rebuild of your editing habits rather than a change of host.

Choosing by who is using it

One person, notes on their own hardware. SiYuan if you want block references, Markdown WYSIWYG and a server you control, with Docker deployment and the Docker image answering on port 6806 as the check our analysis names. Logseq if you want plain files you can put in git, and our analysis tells you to confirm the graph folder is a git repository or otherwise backed up before you trust it. Anytype if you want pages, databases and custom Types to stay on disk with peer-to-peer sync between your own devices, accepting that the desktop client is one half of a two-repository system, since building it means anytype-ts and anytype-heart together.

One person who wants the Notion editor and a phone. AppFlowy is the one to try, because it ships desktop builds plus iOS and Android apps. Read the constraints before you commit: Android 10 or above, ARMv7 not supported.

A small team with realtime editing and structure. Docmost, because realtime collaboration, spaces, groups, permissions management and page history are its documented feature set and it deploys with Docker Compose against PostgreSQL and Redis. Outline is the alternative when you want something lighter to read and Markdown compatibility matters, with the caveat that you are running the source of a hosted product under a source-available licence.

A team that thinks in diagrams and mind maps. AFFiNE, since the merged document and canvas model is the whole point, and the blocks it puts on the canvas include multi-view databases and linked pages.

A company with compliance needs. The AGPL-3.0 candidates are AppFlowy, SiYuan, Logseq and Docmost, and our analysis of Docmost states the obligation plainly: any modification deployed over a network must be released under the same licence. Unmodified internal use is a different conversation from shipping a modified build to customers, and that distinction is worth putting in front of whoever reviews licences. Docmost adds a second layer, because enterprise features in apps/server/src/ee, apps/client/src/ee and packages/ee are covered by a separate enterprise licence rather than the AGPL core. Note also that Notion's own export does not carry database relations, so a compliance-minded migration is a rebuild of your schema before it is anything else.

A developer who wants to embed the thing. Anytype documents a gRPC API and AI Agents, and ships a web clipper extension, so it is the most explicit embedding surface among the seven, with the cost of a source-available licence. AFFiNE is the other candidate for this, since our analysis expects you to run Node 22 and a Rust toolchain from source and to build on Blocksuite. SiYuan exposes a REST API from its Go kernel. Outline's testing guidance refers to its API endpoints, and the README documents an architecture document, a docker-compose path and Sequelize migrations, which is a fair amount to hold in your head before you decide.

What self-hosting each one actually costs

The recurring line items are a stateful database, an upgrade window, and a decision about where collaboration happens. Object storage shows up only once attachments matter, so it is worth asking where uploaded files live before you commit rather than after.

The two server-backed wikis are the heaviest. Docmost deploys with Docker Compose against PostgreSQL and Redis, so you run two stateful services and the app, and the release line moves in version steps, with v0.96.0 released on 2026-09-08 and the last recorded push on 2026-09-27. Outline needs Postgres, Redis and the app as well, and here the documentation is unusually helpful: docker-compose and .env.sample are named as a concrete starting point, migrations run through Sequelize with a named rollback command, container images are published, and .env.sample leaves COLLABORATION_URL empty for normal operation. Our analysis turns that last detail into a question you have to answer, because it tells you to check whether your deployment needs a separate collaboration service.

The single-binary options are cheaper to run and harder to trust. SiYuan ships a Go kernel behind a REST API with Docker deployment in its setup documentation, and our analysis asks you to confirm the Docker image starts and answers on port 6806, and to make sure your sync or backup strategy accounts for the data repo key its FAQ warns about losing. Logseq has no server story in what the project documents, because the graph is files: Markdown or Org-mode in a folder, which our analysis wants you to treat as a git repository or otherwise backed up, with the README recommending automated or regular SQLite backups while the database version is beta.

The workspace apps sit in between. AFFiNE's documented install command is yarn install, and our analysis expects you to run Node 22 and a Rust toolchain from source, with the self-host guide at docs.affine.pro; the releases in that repository are canary builds such as v2026.8.28-canary.1251, so your upgrade tolerance is the constraint. AppFlowy has no one-line installer in our analysis, only a step-by-step self-hosting guide from zero to production, and our analysis tells you to check that the guide covers your deployment target before you plan around it, then to read the changelog for 0.14.0 before moving an existing workspace onto it.

Anytype is the odd one out, and the reason is architectural rather than operational. There is no server for you to run and point at a domain: data lives on your disk first and syncs peer to peer through any-sync. The cost moves to building and updating, where the README's own instructions run from cloning and bun install through a middleware fetch and protobuf generation to a second repository for the engine, plus a protobuf compiler with the well-known .proto files on Linux.

What the licences mean for a company

Four of the seven are AGPL-3.0: AppFlowy, SiYuan, Logseq and Docmost. Our analysis of Docmost puts the rule in one sentence, that any modification deployed over a network must be released under the same licence, and the same licence family covers the other three, so the review you need is the same review. In practice that means running an unmodified copy inside a company is a different question from maintaining a fork that other people can reach, and it is worth writing that distinction down before anyone patches a deployment.

Three candidates are not open source in the OSI sense, and each fails in a different direction. Outline is BSL 1.1, and our analysis calls it source-available rather than open source, telling teams who need open source code to look at the hosted version or a different tool. The README's own framing supports that reading, since it says the repository is the source that runs Outline and that a hosted version is offered for people who just want to use it. Anytype is under the Any Source Available License 1.0, which the README calls open code and our analysis tells you to read in LICENSE.md against how you intend to use the code. AFFiNE is listed under a licence GitHub cannot classify, with the LICENSE file named as the place the terms live, and our analysis adds a sharper instruction for it: confirm which LICENSE file applies to the packages you redistribute, since a monorepo with several packages can carry several files.

There is one more licence-shaped fact in the set, and it is not about any of these projects. SiYuan's README states that most features are free even for commercial use while some features are only available to paid members, so the feature list a reader sees is not entirely the feature list the code covers. That is a documentation fact about where the boundary sits, not a pricing argument.

Taken together, the licence picture says something simple. If your requirement is that a modified copy you host stays private, the four AGPL projects are the ones that require the conversation, and Outline, AFFiNE and Anytype are not a way around it, since each carries its own terms that point back to a licence file. Read the four files before you choose, not after.

Bottom line

Look at AppFlowy first if you want the Notion shape on your own infrastructure, Docmost or Outline if you want a team wiki with realtime editing, AFFiNE if you think in canvases, and SiYuan, Logseq or Anytype if the requirement is one person's notes on hardware they control. What to verify before committing is concrete: read the licence file for the project you pick, confirm the stateful services it needs and the upgrade cadence it implies, check whether your platform is supported, for example Android 10 or above for AppFlowy's mobile client, and find out whether a Notion import path exists for that project, since Notion's export gives you Markdown, CSV, HTML or PDF and database relations do not survive it, so your views get rebuilt either way. The judgement to take away is that the operational bill matters more than the feature list once you are hosting, and that four of these seven are AGPL-3.0, which is a fact about your fork and not about your ability to use them.

Sources

1. Notion official site
2. AppFlowy-IO/AppFlowy repository
3. AppFlowy-IO/AppFlowy README
4. toeverything/AFFiNE repository
5. toeverything/AFFiNE README
6. outline/outline repository
7. outline/outline README
8. siyuan-note/siyuan repository
9. siyuan-note/siyuan README
10. logseq/logseq repository
11. logseq/logseq README
12. anyproto/anytype-ts repository
13. anyproto/anytype-ts README
14. docmost/docmost repository
15. docmost/docmost README