Outline vs SiYuan
A side-by-side comparison of two self-hosted notes & knowledge base options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Outline | SiYuan |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 99 · Excellent | 100 · Excellent |
| Category | Notes & Knowledge Base | Notes & Knowledge Base |
| License | BSL-1.1 | AGPL-3.0 |
| Language | TypeScript | TypeScript |
| Setup difficulty | Medium | Medium |
| Min. RAM | 1,024 MB | 512 MB |
| Deployment | docker | docker, binary, source |
| GitHub stars | ★ 40,682 | ★ 46,488 |
| First released | 2017 | 2020 |
| Replaces | Notion, Confluence | Notion, Evernote |
What are Outline and SiYuan?
Outline
Outline is a fast, collaborative knowledge base and wiki for teams with real-time editing and powerful search. It targets organizations that want a self-hosted documentation hub. It is deployed via Docker with PostgreSQL and Redis.
- Real-time collaborative editing
- Fast full-text search
- SSO and team permissions
- Slack and API integrations
SiYuan
SiYuan is an open-source, privacy-first personal knowledge management system that supports block-level references and bidirectional links. It can run locally or be self-hosted for access across devices.
- Block-level referencing
- Bidirectional links
- Self-hosted or local mode
- End-to-end encrypted sync
Outline vs SiYuan: key differences
Both projects are written in TypeScript. Licensing differs — BSL-1.1 for Outline versus AGPL-3.0 for SiYuan. SiYuan is the lighter option, starting around 512 MB of RAM against 1,024 MB for Outline. Outline is the more established project (first released 2017), while SiYuan arrived in 2020.
Why pick each one
Choose Outline if…
- Polished team wiki
- Great search
- Strong integrations
Watch out for
- Requires Postgres and Redis
- BSL is not fully open source
Choose SiYuan if…
- Powerful block-based model
- Works offline and self-hosted
Watch out for
- Documentation strongest in Chinese
- Some advanced features are paid
Frequently asked questions
Is Outline or SiYuan better?
Neither is universally better. SiYuan has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Outline and SiYuan free and open-source?
Yes. Outline is licensed under BSL-1.1 and SiYuan under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run Outline and SiYuan with Docker?
Outline: yes. SiYuan: yes.
Which is lighter on resources, Outline or SiYuan?
SiYuan has the smaller minimum footprint at 512 MB of RAM, compared to about 1,024 MB for Outline. Real-world usage depends on library size, user count, and enabled features.