AFFiNE vs SiYuan
Two serious open knowledge tools, two very different personalities. AFFiNE wants to replace your docs + whiteboard + workspace stack. SiYuan wants to give power users a deep block-based knowledge system they truly control.
Every idea can become an addressable unit.
References stay connected across documents.
Surface knowledge by structure, not folders alone.
Pull the same block into multiple contexts.
Why this keyword belongs on the site
The exact comparison SERP is still thin. One recent dedicated self-hosted comparison exists, plus aggregator coverage, but there is nowhere near the saturation you see around Notion or Obsidian. Meanwhile both projects have large, active GitHub communities and fit the same high-intent “open-source / self-hosted / privacy-first knowledge base” search cluster.
Choose the interface philosophy first.
AFFiNE is easier to understand if you think in pages, whiteboards and projects. SiYuan becomes more powerful if you think in blocks, references, queries and reusable knowledge.
Its strongest differentiator is the combination of conventional docs with an “Edgeless” canvas and workspace-style collaboration. AFFiNE Community Edition is currently available for self-hosting under MIT terms.
Fine-grained references, two-way links, custom attributes, SQL query embeds, databases, flashcards, web clipping and Docker deployment make it unusually deep for technical and long-term personal knowledge systems.
Where the products really separate.
Both can be local and self-hosted. The bigger question is what happens after your data is inside.
| Decision | AFFiNE | SiYuan | Edge |
|---|---|---|---|
| Core mental model | Docs + databases + infinite/Edgeless canvas | Documents made from addressable content blocks | Preference |
| Visual whiteboarding | A core product feature; visual work and docs live together | Supports diagrams/charts, but visual canvas is not the central model | AFFiNE |
| Block references | Flexible block editor and linking | Fine-grained block reference, embedding and two-way links are core strengths | SiYuan |
| Advanced querying | Databases and workspace views | Custom attributes plus SQL query embeds for deep retrieval | SiYuan |
| Self-hosting | Official Docker/self-host path; Community Edition available | Docker deployment and local-first/self-hosted workflows are core use cases | Both strong |
| Licensing | Community Edition currently MIT; enterprise/backend licensing differs by edition | Main SiYuan repository is AGPL-3.0 | Different models |
| Study features | Strong documents, visual mapping and AI-assisted knowledge workflows | PDF annotation linking, flashcards/spaced repetition, web clipping | SiYuan |
| Team / workspace feel | Closer to modern collaborative workspace products | Primarily feels like deep personal knowledge software | AFFiNE |
Same knowledge. Different architecture.
Imagine researching a new topic. The two apps encourage very different paths from raw information to understanding.
The long-tail opportunity is bigger than the exact keyword.
People in PKM and self-hosted communities repeatedly ask for the same things: a real open-source Notion alternative, local data, less dependence on cloud vendors, strong databases, and tools that do not force one style of thinking.
“I want a real open-source Notion alternative I can keep local.”
SiYuan is actively recommended in that exact kind of 2026 PKM discussion.“Can I get docs, whiteboards and databases without using Notion + Miro?”
That is almost exactly the market position AFFiNE is pursuing.“Which self-hosted knowledge tool will still work when my setup gets complicated?”
This lets us target future pages around Docker, sync, licensing, block references, web clipping and AI.AFFiNE for the workspace. SiYuan for the knowledge engine.
If your ideal app feels like Notion and Miro merged into one local/self-hostable workspace, start with AFFiNE. If you want granular block references, powerful retrieval and a serious long-term PKM system, start with SiYuan.
Sources: AFFiNE official · AFFiNE GitHub · AFFiNE enterprise/self-host · SiYuan GitHub · SelfHostIndex comparison · LibHunt comparison · Reddit PKM discussion.