Outline: The Open-Source Team Knowledge Base for Modern Organizations

Every team accumulates knowledge—onboarding guides, architecture decisions, meeting notes, runbooks, API documentation, design specs, and the countless "how we do things here" documents that keep an organization running. But where does it all live? Scattered across Google Docs, Slack messages, Notion pages, random Confluence spaces, and the personal notes of employees who left three years ago. This fragmentation is not just annoying—it is a productivity killer. Outline exists to solve this problem: a beautiful, open-source team knowledge base that combines the real-time collaboration of Notion with the structured documentation of Confluence, all under your control.

1. What Is Outline?

Outline is an open-source, self-hosted team wiki and knowledge base platform. It provides a clean, modern interface for creating, organizing, and sharing structured documentation within teams and organizations. Launched in 2017, Outline was built to fill the gap between lightweight note-taking apps (which lack structure and permissions) and heavyweight enterprise wikis (which are slow, ugly, and expensive).

The problem Outline solves is knowledge fragmentation and loss. When team knowledge is scattered across a dozen tools, it cannot be found when needed. When it lives in someone's personal notes, it disappears when they leave. When it is locked in a proprietary platform, it cannot be exported or self-hosted. Outline provides a single, searchable, collaborative home for team knowledge—with the structure to keep it organized and the openness to keep it yours.

Outline is built with a focus on the writing experience. The editor is a block-based Markdown editor (similar to Notion's) that supports rich content—code blocks, tables, embeds, checkboxes, and more—while maintaining clean, portable Markdown output. Documents are organized into collections (which act like top-level categories) and can be nested hierarchically, tagged, and linked together.

The project is licensed under the Business Source License (BSL), which allows free use for teams under a certain size and self-hosting, while requiring larger organizations to purchase a commercial license. This model allows the project to be sustainable while remaining accessible to small teams and individual users.

2. Key Features

Real-Time Collaborative Editing

Outline supports real-time multi-user editing, similar to Google Docs or Notion:

• Live cursors: see where other users are typing in real-time
• Simultaneous editing: multiple users can edit the same document at the same time
• Conflict-free editing: uses Yjs (a CRDT library) to ensure changes merge cleanly without conflicts
• Presence indicators: see who is currently viewing or editing each document

Block-Based Markdown Editor

Outline's editor is a hybrid of Markdown and rich text:

• Slash commands: type / to insert blocks (headings, lists, tables, code, images, etc.)
• Markdown shortcuts: type ## to create a heading, - for a list, ``` ` `` for a code block
• Drag and drop: rearrange blocks by dragging them
• Code blocks: with syntax highlighting for 100+ languages
• Tables: full table support with formatting
• Checklists: interactive checkboxes that can be toggled
• Embeds: embed videos (YouTube, Vimeo), code (CodePen, GitHub Gists), and other content
• Math support: render LaTeX math equations
• Mermaid diagrams: render flowcharts, sequence diagrams, and more
• Image galleries: drag-and-drop image uploads with automatic optimization

• Backend: Written in Node.js with TypeScript, using the Koa web framework. The backend exposes a RESTful API and uses a job queue (Redis-based) for background tasks.
• Frontend: Built with React and TypeScript, using MobX for state management and Styled Components for styling. The editor is built on top of ProseMirror (the same editor framework used by Atlassian).
• Real-Time Collaboration: Uses Yjs (a Conflict-free Replicated Data Type library) for real-time collaborative editing. Yjs ensures that concurrent edits merge cleanly without conflicts.
• Database: Uses PostgreSQL as the primary database, leveraging its full-text search capabilities (tsvector and tsquery) for search functionality.
• Cache and Queue: Uses Redis for caching, session storage, and the background job queue.
• File Storage: Supports local filesystem, AWS S3, Google Cloud Storage, Azure Blob Storage, and MinIO (self-hosted S3-compatible storage) for file uploads.
• Authentication: Supports email/password, Google, Slack, Microsoft, OIDC (OpenID Connect), and LDAP (via OIDC bridge).
• Search: Full-text search is built on PostgreSQL's native full-text search, with optional support for Algolia (for enhanced search on cloud deployments).

version: "3.8"

services:

  outline:

    image: outlinewiki/outline:latest

    container_name: outline

    environment:

      - NODE_ENV=production

      - SECRET_KEY=generate_a_random_secret_key_here

      - UTILS_SECRET=generate_another_random_secret_here

      - DATABASE_URL=postgres://outline:outline_password@postgres:5432/outline

      - REDIS_URL=redis://redis:6379

      - URL=https://wiki.yourdomain.com

      - PORT=3000

      - FORCE_HTTPS=true

      - ENABLE_UPDATES=true

      - WEB_CONCURRENCY=1

      - MAXIMUM_IMPORT_SIZE=5120000

      - DEFAULT_LANGUAGE=en_US

      # Authentication (choose at least one)

      - GOOGLE_CLIENT_ID=your_google_client_id

      - GOOGLE_CLIENT_SECRET=your_google_client_secret

      - SLACK_CLIENT_ID=your_slack_client_id

      - SLACK_CLIENT_SECRET=your_slack_client_secret

      # Email

      - SMTP_HOST=smtp.yourprovider.com

      - SMTP_PORT=587

      - SMTP_USERNAME=your_email

      - SMTP_PASSWORD=your_email_password

      - [email protected]

      # File storage (local)

      - FILE_STORAGE=local

      - FILE_STORAGE_LOCAL_ROOT=/var/lib/outline/data

    volumes:

      - outline_data:/var/lib/outline/data

    ports:

      - "3000:3000"

    depends_on:

      - postgres

      - redis

    restart: unless-stopped

postgres:

    image: postgres:16-alpine

    container_name: outline-postgres

    environment:

      - POSTGRES_USER=outline

      - POSTGRES_PASSWORD=outline_password

      - POSTGRES_DB=outline

    volumes:

      - postgres_data:/var/lib/postgresql/data

    restart: unless-stopped

redis:

    image: redis:7-alpine

    container_name: outline-redis

    restart: unless-stopped

volumes:

  outline_data:

  postgres_data:

   mkdir -p ~/outline

   cd ~/outline

   

   openssl rand -hex 32  # Use for SECRET_KEY

   openssl rand -hex 32  # Use for UTILS_SECRET

   

4. Set up authentication:
You need at least one authentication provider. The easiest options are:
- Google: Create OAuth credentials at Google Cloud Console
- Slack: Create a Slack app at api.slack.com/apps

Set the redirect URLs to:
- Google: https://wiki.yourdomain.com/auth/google.callback
- Slack: https://wiki.yourdomain.com/auth/slack.callback

   docker compose up -d

   

   docker exec outline yarn db:migrate --env production-ssl-disabled

   

   wiki.yourdomain.com {

       reverse_proxy localhost:3000

   }

   

8. Access Outline:
Navigate to https://wiki.yourdomain.com` and sign in with your configured authentication provider. The first user becomes the workspace admin.

9. Configure workspace settings:
Go to Settings → Workspace to configure:
- Workspace name and logo
- Default language
- Allowed domains (restrict signups to your domain)
- Collection defaults

Using S3-Compatible Storage (Recommended for Production)

For production deployments, use S3-compatible storage instead of local storage:

environment:
  - FILE_STORAGE=s3
  - AWS_S3_ACCELERATE_URL=  # Leave empty unless using transfer acceleration
  - AWS_ACCESS_KEY_ID=your_access_key
  - AWS_SECRET_ACCESS_KEY=your_secret_key
  - AWS_REGION=us-east-1
  - AWS_S3_UPLOAD_BUCKET_URL=https://s3.amazonaws.com
  - AWS_S3_UPLOAD_BUCKET_NAME=your-bucket-name
  - AWS_S3_FORCE_PATH_STYLE=true  # For MinIO
  - AWS_S3_ACL=private

For self-hosted S3 storage, use MinIO:

  minio:
    image: minio/minio:latest
    container_name: outline-minio
    environment:
      - MINIO_ROOT_USER=outline
      - MINIO_ROOT_PASSWORD=outline_minio_password
    volumes:
      - minio_data:/data
    ports:
      - "9000:9000"
    command: server /data
    restart: unless-stopped

5. Comparison with Alternatives

| Feature | Outline | Notion | Confluence | BookStack |
|---|---|---|---|---|
| Open Source | Yes (BSL) | No | No | Yes (MIT) |
| Self-Hosting | Yes | No | Yes (Data Center) | Yes |
| Real-Time Collaboration | Yes (Yjs/CRDT) | Yes | Yes (limited) | No |
| Editor Type | Block-based Markdown | Block-based proprietary | Rich text / Wiki markup | WYSIWYG Markdown |
| Full-Text Search | Yes (PostgreSQL) | Yes | Yes (Lucene) | Yes (MySQL) |
| SSO/SAML | Yes (OIDC, Google, Slack) | Enterprise only | Yes | LDAP/SAML2 |
| API | REST API | REST API | REST API | REST API |
| Slack Integration | Yes (deep) | Yes (basic) | Yes (basic) | No |
| Export | Markdown, HTML, PDF | Markdown, HTML, PDF | HTML, XML, PDF | HTML, Markdown, PDF |
| Resource Usage | Moderate (~500MB) | N/A (cloud) | High (~4GB+) | Low (~200MB) |
| Database | PostgreSQL | Proprietary | PostgreSQL/MySQL | MySQL/MariaDB |
| Pricing | Free (self-host) / Cloud plans | Free tier; $8-20/user/mo | $5-10/user/mo | Free (self-host) |
| Best For | Tech-savvy teams | General productivity | Enterprise | Simple wikis |

Notion is the most popular team knowledge tool, with a beautiful interface, massive template ecosystem, and excellent collaboration features. However, it is cloud-only (no self-hosting), stores data in a proprietary format, and can become expensive for larger teams. Notion is also a general-purpose tool (databases, project management, etc.) rather than a focused knowledge base, which can be a strength or a weakness depending on your needs.

Confluence is the enterprise standard for team documentation, deeply integrated with the Atlassian ecosystem (Jira, Bitbucket, etc.). It is powerful but slow, expensive, and its interface feels dated compared to modern alternatives. Self-hosting Confluence Data Center is complex and resource-intensive. It is best suited for large enterprises already invested in the Atlassian stack.

BookStack is another open-source wiki platform that is simpler and lighter than Outline. It uses a WYSIWYG editor (rather than a block-based editor) and is easier to set up, but lacks real-time collaboration, has a less polished interface, and does not support the same depth of integrations. It is a good choice for small teams that want a simple wiki without the complexity of Outline.

Outline occupies the sweet spot for teams that want a focused, beautiful knowledge base with real-time collaboration, modern integrations, and the ability to self-host. Its block-based Markdown editor is the best of both worlds—rich enough for complex documents, portable enough to avoid lock-in.

6. FAQ

Can I use Outline for personal note-taking?

Yes. While Outline is designed for team knowledge bases, it works perfectly well for personal use. You can create collections for different areas of your life (Personal, Work, Learning, etc.) and use it as a self-hosted alternative to Notion or Obsidian. The real-time collaboration features simply go unused if you are the only user.

How does Outline handle data export?

Outline takes data portability seriously:

• Individual documents: export as Markdown, HTML, or PDF
• Collections: export all documents in a collection as a ZIP of Markdown files
• Full workspace: export all data via the API or the workspace export feature
• Format: all content is stored as Markdown, so exports are clean and portable

Is Outline suitable for large organizations?

Outline works well for organizations of up to a few hundred users. For very large organizations, consider:

• SSO: configure OIDC or SAML for enterprise authentication
• Performance: ensure your PostgreSQL and Redis instances are properly sized
• Search: for very large document sets, consider integrating Algolia for enhanced search
• Compliance: Outline does not currently offer SOC 2 or HIPAA compliance certifications (the cloud-hosted version may offer these in the future)

Can I integrate Outline with my existing tools?

Yes. Outline integrates with:

• Slack: deep integration (search, notifications, authentication)
• Microsoft Teams: notifications and authentication
• Google Workspace: authentication and document import
• GitHub: embed gists and link to issues
• Figma: embed Figma designs
• Loom, YouTube, Vimeo: embed videos
• CodePen, Glitch: embed code
• Any tool with a REST API: use Outline's API for custom integrations

7. Who Should Use This?

Outline is ideal for:

• Engineering and product teams that need a structured knowledge base for architecture docs, runbooks, and team wikis
• Startups and small companies that want a Notion-like experience without the recurring cost
• Open-source projects that need a self-hosted documentation platform
• Remote teams that rely on asynchronous communication and need a central knowledge hub
• Organizations with data sovereignty requirements that need self-hosted documentation
• Teams migrating from Notion that want to self-host while keeping a similar experience

• The BSL license means very large organizations (100+ users) need a commercial license
• Requires PostgreSQL and Redis, making it more complex to deploy than simpler alternatives like BookStack
• No offline mode (unlike tools like Obsidian or Notion's mobile app)
• The real-time collaboration features require a WebSocket connection, which may need configuration behind some reverse proxies
• No built-in diagramming tool (though Mermaid and embeds like Excalidraw are supported)
• Does not replace a full project management tool (no task boards, databases, or calendars like Notion)

Verdict

Outline is the open-source knowledge base that finally feels modern. Its block-based Markdown editor provides a writing experience that rivals Notion, while its real-time collaboration, full-text search, structured collections, and deep integrations make it a complete solution for team knowledge management. The ability to self-host, combined with the portable Markdown format and comprehensive API, means your knowledge stays yours—no lock-in, no proprietary formats, no cloud dependency. For any team that values both quality and control, Outline is an outstanding choice that turns scattered documentation into a cohesive, searchable, collaborative knowledge base.

GitHub Repository: outline/outline