Docmost vs Outline vs AFFiNE: Open Source Knowledge Bases in 2026
Choosing the Right Open Source Knowledge Base
Confluence costs $5.16-$10.50/user/month. Notion is $10-18/user/month. GitBook charges $6.70+/user/month for team plans. For a 20-person team, these costs add up to $1,200-4,320/year for what is fundamentally a documentation tool.
Three open source alternatives stand out in 2026: Docmost for simple team wikis, Outline for production-ready knowledge management, and AFFiNE for teams that need both documents and whiteboards.
Each serves a different use case. This comparison helps you choose.
TL;DR
- Outline (29K+ stars): Best production-ready knowledge base for teams. Mature, stable, great auth integration. Best for growing teams who need reliability now.
- Docmost (8K+ stars): Best lightweight wiki for small teams. Dead simple to deploy, zero learning curve. Best when you just need a team wiki.
- AFFiNE (62K+ stars): Best when you need whiteboard + docs together. Unique canvas/page hybrid. Best for design and product teams.
Quick Comparison
| Feature | Outline | Docmost | AFFiNE |
|---|---|---|---|
| GitHub Stars | 29K+ | 8K+ | 62K+ |
| Deployment complexity | Low | Low | Medium |
| Documents | Yes | Yes | Yes |
| Databases/tables | No | No | Limited |
| Whiteboard | No | No | Yes |
| Inline comments | Yes | Yes | No |
| Auth integrations | Excellent | Good | Basic |
| Team management | Yes | Yes | Yes |
| Real-time collab | Yes | Yes | Yes |
| Search | Excellent | Good | Basic |
| API | Comprehensive | Growing | Limited |
| License | BSL 1.1 | AGPL-3.0 | MIT |
Outline — Most Production-Ready Choice
Outline (29K+ GitHub stars) is the most mature and production-ready open source knowledge base. It's not trying to replicate Notion's databases or AFFiNE's whiteboards — it's a focused, polished team knowledge base that works reliably at scale.
What Makes It Stand Out
Authentication: Outline's auth system is its standout feature. It supports Google Workspace, Slack, Azure AD, GitHub, Okta, and any OIDC-compatible provider. For teams already using one of these, login is seamless. This is more mature than most alternatives.
Clean editor: Markdown-based editor with slash commands, code blocks, tables, images, and embeds. Fast, reliable, and consistent — no surprises.
Collections: Organize documents in hierarchical collections (like Confluence spaces). Share collections with specific teams, set permissions per collection, and manage access centrally.
Version history: Every document edit is tracked. View the history of any document, see who changed what, and restore previous versions.
API: Comprehensive REST API covering documents, collections, users, and groups. Excellent for integrations, data export, and automation.
Search: Fast full-text search across all documents. Works well even on large knowledge bases.
Templates: Create and share document templates for meeting notes, project proposals, specs, etc.
Self-Hosting Requirements
services:
outline:
image: outlinewiki/outline
env_file: ./docker.env
ports:
- "3000:3000"
storage:
image: minio/minio
redis:
image: redis
postgres:
image: postgres:16
Three core services: the Outline app, PostgreSQL (database), and Redis (caching). Optional MinIO for local file storage instead of S3.
Auth requirement: Outline requires an external auth provider — it has no built-in username/password system. You need Google, Slack, Azure AD, or another OIDC provider configured. For teams without an existing provider, this is the main barrier.
License note: Outline uses BSL 1.1 (Business Source License), not a traditional open source license. Converts to Apache 2.0 after 3 years. Production use restrictions may apply — read the license for your use case.
Best for: Teams with 10-200+ people who need a stable, well-maintained knowledge base and already have an OIDC auth provider (Google Workspace, Slack, Azure AD).
Docmost — Best for Simple Team Wikis
Docmost (8K+ stars) is what you use when the requirement is simple: "we need a place to write and share team documentation." No databases, no whiteboards, no complex auth — just a clean, functional wiki.
What Makes It Stand Out
Simplicity: Docmost has the smallest feature set of the three tools, but that's the point. Everything you need, nothing you don't.
Spaces: Organize content into spaces — similar to Confluence's space concept. Different teams or projects get their own space with independent permissions.
Minimal infrastructure: Just the Docmost app and PostgreSQL. Optional Redis. This is the lightest deployment of the three tools.
services:
docmost:
image: docmost/docmost:latest
ports:
- "3000:3000"
environment:
- DATABASE_URL=postgresql://...
- APP_SECRET=your-secret
db:
image: postgres:16-alpine
Two containers to deploy. No auth provider dependency — Docmost has built-in email/password auth plus social login options.
User management: Invite users by email, set roles (owner, admin, member), and manage space permissions. Straightforward without complexity.
Inline comments: Comment on specific text within documents for review workflows.
When Docmost Is the Right Choice
Docmost is best when:
- Your team is small (under 50 people)
- You want to be running in under 30 minutes
- You don't have an existing OIDC provider (Outline's main requirement)
- You value simplicity over features
Limitations
Docmost is newer than Outline and lacks some features:
- Less mature API than Outline
- Fewer auth provider integrations
- Less battle-tested for large deployments
- Smaller community for support
Best for: Small teams (5-30 people) who want a functional wiki deployed quickly with minimal infrastructure.
AFFiNE — Best for Docs + Whiteboards
AFFiNE (62K+ GitHub stars) takes a fundamentally different approach. It's not just a document tool — it's a unified workspace that combines documents (page mode) with an infinite canvas whiteboard (edgeless mode).
What Makes It Stand Out
Canvas + docs hybrid: Switch between structured document view and freeform whiteboard for the same content. Drag document blocks onto the canvas to create visual arrangements. This is AFFiNE's unique value.
Edgeless mode: An infinite canvas where you can draw, add notes, create mind maps, sketch diagrams, and arrange ideas spatially. Similar to Miro, but integrated with your documents.
Block-based architecture: Everything in AFFiNE is a block — text, image, table, code, database, whiteboard element. Blocks can be rearranged, referenced, and embedded.
Offline-first: AFFiNE's desktop application (Electron) works fully offline. Documents sync when you're back online.
Local-first option: Data can live locally on your device, not just on a server.
Self-Hosting
services:
affine:
image: ghcr.io/toeverything/affine-graphql:stable
ports:
- "3010:3010"
redis:
image: redis
postgres:
image: postgres:latest
Three services. AFFiNE's self-hosting documentation has improved significantly from earlier versions.
Limitations
- Document-only search is less mature than Outline
- Auth integration options are fewer (no LDAP, limited SAML)
- The whiteboard focus means pure document workflows can feel cluttered
- API is less comprehensive than Outline
- Self-hosting documentation, while improved, has fewer community resources than Outline
Best for: Design teams, product managers, and teams who need both structured documentation and visual thinking tools in one self-hosted platform.
Three-Way Comparison: Core Tasks
Creating a Team Wiki Entry
Outline: Navigate to collection → New document → Write. Clean editing experience. Auto-saved, version history automatic.
Docmost: Select space → New page → Write. Equally simple. Inline commenting available immediately.
AFFiNE: Choose page mode → New page → Write. Nearly identical to the others for pure document creation.
Winner: Tie between Outline and Docmost for simplicity.
Setting Up New Team Member Access
Outline: Invite via email → Auth provider handles login → Assign to collections. BUT requires the auth provider to be configured first.
Docmost: Invite via email → They set a password → Assign to spaces. Works immediately with built-in auth.
AFFiNE: Invite to workspace → They create an account → Access granted.
Winner: Docmost (no auth provider dependency).
Adding a Visual Diagram to Documentation
Outline: Embed Excalidraw, Miro, or draw.io via iframe/link. Not native.
Docmost: Similar embed options. Not native.
AFFiNE: Draw diagrams natively on the canvas, embed in documents. First-class feature.
Winner: AFFiNE (by a large margin for visual content).
Cost Comparison: Commercial vs Self-Hosted
Notion Business (20 Users)
| Plan | Monthly | Annual |
|---|---|---|
| Plus | $10/user | $2,400 |
| Business | $18/user | $4,320 |
Self-Hosted (20 Users)
| Tool | Server | Annual |
|---|---|---|
| Outline (Hetzner CPX21) | $6.50/mo | $78 |
| Docmost (Hetzner CAX11) | $4/mo | $48 |
| AFFiNE (Hetzner CPX21) | $6.50/mo | $78 |
The server cost is essentially the same for all three. You're choosing based on features, not cost.
Decision Guide
Choose Outline if:
- You have 20+ team members
- You already have Google Workspace, Slack, or Azure AD for auth
- Stability and maturity matter more than features
- You need the most comprehensive API and integrations
Choose Docmost if:
- You're a small team (under 30 people)
- You want to be running in 30 minutes
- You don't have an existing OIDC provider
- Simplicity is more important than enterprise features
Choose AFFiNE if:
- Your team does design, product, or visual thinking work
- You need whiteboard + documentation in one tool
- You want to replace both Miro and Notion
- Visual-first workflows matter to your team
Find Your Knowledge Base
Browse all knowledge base and wiki tools on OSSAlt — compare Outline, Docmost, AFFiNE, AppFlowy, BookStack, and every other open source knowledge management platform with deployment guides and feature comparisons.