Best Open Source Alternatives to Notion 2026

TL;DR

Notion charges $10/user/month. The best open source alternatives: AppFlowy (AGPL 3.0, ~60K GitHub stars, Rust/Flutter) for a full Notion-like experience with databases, kanban, and docs; AFFiNE (MIT, ~45K stars, TypeScript) for a whiteboard+doc hybrid; and Outline (BSL, ~28K stars, TypeScript/React) for team wikis. All self-host via Docker and store your data on your server.

Key Takeaways

AppFlowy: AGPL 3.0, ~60K stars — Rust backend + Flutter frontend, databases, kanban, docs, grids
AFFiNE: MIT, ~45K stars — doc + whiteboard + database in one, local-first with optional sync server
Outline: BSL, ~28K stars — focused team wiki/knowledge base, excellent Slack/Notion import
SiYuan: AGPL 3.0, ~30K stars — local-first block editor, full offline, strong search
Logseq: AGPL 3.0, ~33K stars — outliner/graph notes, plain Markdown files, no database backend
Pick by use case: Team wiki → Outline; Full Notion replacement → AppFlowy; Whiteboard hybrid → AFFiNE

Comparison Table

Feature	AppFlowy	AFFiNE	Outline	SiYuan
License	AGPL 3.0	MIT	BSL 1.1	AGPL 3.0
GitHub Stars	~60K	~45K	~28K	~30K
Backend	Rust	Node.js	Node.js	Go
Frontend	Flutter	TypeScript	React	TypeScript
Databases/grids	Yes	Yes	No	Yes
Kanban boards	Yes	Yes	No	Yes
Whiteboard	No	Yes	No	No
Team wiki	Yes	Yes	Yes	No
Notion import	Yes	Yes	Yes	No
Local-first option	Yes	Yes	No	Yes
Self-host Docker	Yes	Yes	Yes	Yes
Mobile apps	Yes	Yes	Limited	Yes
Real-time collab	Yes	Yes	Yes	No

Option 1: AppFlowy

AppFlowy is the closest 1:1 Notion replacement. Databases with multiple views (grid, board, calendar, gallery), rich text docs, nested pages — all in a Flutter desktop/mobile app or web.

# docker-compose.yml
services:
  appflowy_cloud:
    image: appflowyinc/appflowy_cloud:latest
    container_name: appflowy_cloud
    restart: unless-stopped
    ports:
      - "8000:8000"
    environment:
      RUST_LOG: info
      APPFLOWY_DATABASE_URL: "postgres://appflowy:${POSTGRES_PASSWORD}@postgres:5432/appflowy"
      APPFLOWY_REDIS_URI: "redis://redis:6379"
      APPFLOWY_GOTRUE_JWT_SECRET: "${JWT_SECRET}"
      APPFLOWY_GOTRUE_JWT_EXP: 7200
      APPFLOWY_GOTRUE_BASE_URL: "http://gotrue:9999"
      APPFLOWY_GOTRUE_EXT_URL: "https://appflowy.yourdomain.com"
    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_started

  gotrue:
    image: appflowyinc/gotrue:latest
    container_name: appflowy_gotrue
    restart: unless-stopped
    environment:
      GOTRUE_SITE_URL: "https://appflowy.yourdomain.com"
      GOTRUE_JWT_SECRET: "${JWT_SECRET}"
      GOTRUE_DB_DRIVER: "postgres"
      DATABASE_URL: "postgres://supabase_auth_admin:${POSTGRES_PASSWORD}@postgres:5432/supabase_auth"
      GOTRUE_SMTP_HOST: "smtp.yourdomain.com"
      GOTRUE_SMTP_PORT: 587
      GOTRUE_SMTP_USER: "${SMTP_USER}"
      GOTRUE_SMTP_PASS: "${SMTP_PASS}"
      GOTRUE_MAILER_AUTOCONFIRM: "false"
      API_EXTERNAL_URL: "https://appflowy.yourdomain.com"
    depends_on:
      - postgres

  postgres:
    image: pgvector/pgvector:pg16
    container_name: appflowy_postgres
    restart: unless-stopped
    environment:
      POSTGRES_USER: appflowy
      POSTGRES_PASSWORD: "${POSTGRES_PASSWORD}"
      POSTGRES_DB: appflowy
    volumes:
      - postgres_data:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U appflowy"]
      interval: 10s
      start_period: 20s

  redis:
    image: redis:7-alpine
    container_name: appflowy_redis
    restart: unless-stopped
    volumes:
      - redis_data:/data

  minio:
    image: minio/minio:latest
    container_name: appflowy_minio
    restart: unless-stopped
    command: server /data --console-address ":9001"
    environment:
      MINIO_ROOT_USER: "${MINIO_USER}"
      MINIO_ROOT_PASSWORD: "${MINIO_PASSWORD}"
    volumes:
      - minio_data:/data

volumes:
  postgres_data:
  redis_data:
  minio_data:

# .env
POSTGRES_PASSWORD=your-secure-db-password
JWT_SECRET=your-32-char-secret
SMTP_USER=you@yourdomain.com
SMTP_PASS=smtp-password
MINIO_USER=appflowy
MINIO_PASSWORD=your-minio-password

docker compose up -d

AppFlowy Caddy Config

appflowy.yourdomain.com {
    reverse_proxy localhost:8000
}

Connect AppFlowy Desktop

Download AppFlowy Desktop
Click Sign In → Self-hosted server
Enter: https://appflowy.yourdomain.com
Create account / sign in

AppFlowy Database Views

AppFlowy databases support multiple views of the same data:

Grid: Spreadsheet-style with filtered/sorted rows
Board: Kanban grouped by any property
Calendar: Date-based view
Gallery: Card layout for visual content

Database: Project Tasks
├── Grid view: All tasks with status, priority, assignee
├── Board view: Kanban grouped by "Status" (Todo/In Progress/Done)
└── Calendar view: Grouped by "Due Date"

Option 2: AFFiNE

AFFiNE combines a block-based doc editor with an infinite whiteboard — useful for design thinking, architecture diagrams, and visual note-taking alongside written docs.

# docker-compose.yml
services:
  affine:
    image: ghcr.io/toeverything/affine-graphql:stable
    container_name: affine
    restart: unless-stopped
    ports:
      - "3010:3010"
    volumes:
      - affine_config:/root/.affine/config
      - affine_storage:/root/.affine/storage
    environment:
      NODE_OPTIONS: "--import=./scripts/register.js"
      AFFINE_CONFIG_PATH: "/root/.affine/config"
      REDIS_SERVER_HOST: redis
      DATABASE_URL: "postgresql://affine:${POSTGRES_PASSWORD}@postgres:5432/affine"
      NEXTAUTH_URL: "https://affine.yourdomain.com"
      AFFINE_SERVER_HTTPS: "true"
      AFFINE_SERVER_HOST: "affine.yourdomain.com"
      AFFINE_SERVER_PORT: "3010"
      AFFINE_ADMIN_EMAIL: "${ADMIN_EMAIL}"
      AFFINE_ADMIN_PASSWORD: "${ADMIN_PASSWORD}"
    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_started

  redis:
    image: redis:7-alpine
    container_name: affine_redis
    restart: unless-stopped

  postgres:
    image: postgres:16-alpine
    container_name: affine_postgres
    restart: unless-stopped
    environment:
      POSTGRES_USER: affine
      POSTGRES_PASSWORD: "${POSTGRES_PASSWORD}"
      POSTGRES_DB: affine
    volumes:
      - postgres_data:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U affine"]
      interval: 10s
      start_period: 30s

volumes:
  affine_config:
  affine_storage:
  postgres_data:

affine.yourdomain.com {
    reverse_proxy localhost:3010
}

AFFiNE Local-First Mode

AFFiNE also works entirely offline — no server needed:

Download AFFiNE Desktop
Data stored in ~/.affine/ as SQLite
Self-host only needed for team sync

Option 3: Outline (Team Wiki)

Outline is purpose-built for team knowledge bases — clean editor, nested collections, Slack integration, full-text search. Less of a database tool, more of a clean wiki.

# docker-compose.yml
services:
  outline:
    image: outlinewiki/outline:latest
    container_name: outline
    restart: unless-stopped
    ports:
      - "3000:3000"
    environment:
      SECRET_KEY: "${SECRET_KEY}"
      UTILS_SECRET: "${UTILS_SECRET}"
      DATABASE_URL: "postgres://outline:${POSTGRES_PASSWORD}@postgres:5432/outline"
      REDIS_URL: "redis://redis:6379"
      URL: "https://wiki.yourdomain.com"
      PORT: 3000
      # Auth (choose one):
      OIDC_CLIENT_ID: "${OIDC_CLIENT_ID}"
      OIDC_CLIENT_SECRET: "${OIDC_CLIENT_SECRET}"
      OIDC_AUTH_URI: "${OIDC_AUTH_URI}"
      OIDC_TOKEN_URI: "${OIDC_TOKEN_URI}"
      OIDC_USERINFO_URI: "${OIDC_USERINFO_URI}"
      # Or Google auth:
      # GOOGLE_CLIENT_ID: "${GOOGLE_CLIENT_ID}"
      # GOOGLE_CLIENT_SECRET: "${GOOGLE_CLIENT_SECRET}"
      # Storage (S3 or local):
      FILE_STORAGE: "local"
      FILE_STORAGE_LOCAL_ROOT_DIR: "/var/lib/outline/data"
      # Email:
      SMTP_HOST: "smtp.yourdomain.com"
      SMTP_PORT: 587
      SMTP_USERNAME: "${SMTP_USER}"
      SMTP_PASSWORD: "${SMTP_PASS}"
      SMTP_FROM_EMAIL: "outline@yourdomain.com"
    volumes:
      - outline_data:/var/lib/outline/data
    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_started

  postgres:
    image: postgres:16-alpine
    restart: unless-stopped
    environment:
      POSTGRES_USER: outline
      POSTGRES_PASSWORD: "${POSTGRES_PASSWORD}"
      POSTGRES_DB: outline
    volumes:
      - postgres_data:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U outline"]
      interval: 10s
      start_period: 20s

  redis:
    image: redis:7-alpine
    restart: unless-stopped

volumes:
  outline_data:
  postgres_data:

wiki.yourdomain.com {
    reverse_proxy localhost:3000
}

Outline Auth: Using Authentik (OIDC)

If you're running Authentik for SSO:

Authentik Admin → Applications → Providers → Create → OAuth2/OpenID Provider
Name: Outline, Redirect URI: https://wiki.yourdomain.com/auth/oidc.callback
Copy Client ID, Secret, and OIDC endpoints into Outline env vars

OIDC_CLIENT_ID=your-client-id
OIDC_CLIENT_SECRET=your-client-secret
OIDC_AUTH_URI=https://auth.yourdomain.com/application/o/outline/authorize/
OIDC_TOKEN_URI=https://auth.yourdomain.com/application/o/outline/token/
OIDC_USERINFO_URI=https://auth.yourdomain.com/application/o/outline/userinfo/
OIDC_DISPLAY_NAME="Your SSO"

Import from Notion

Outline has a Notion importer:

In Notion: Settings → Export → Markdown & CSV (export all workspace)
In Outline: Settings → Import → Notion → upload the ZIP

Option 4: SiYuan (Local-First, Offline)

For individuals who want everything local with optional sync:

services:
  siyuan:
    image: b3log/siyuan:latest
    container_name: siyuan
    restart: unless-stopped
    ports:
      - "6806:6806"
    volumes:
      - siyuan_workspace:/siyuan/workspace
    environment:
      TZ: America/Los_Angeles
    command: ["--workspace=/siyuan/workspace", "--accessAuthCode=${ACCESS_CODE}"]

volumes:
  siyuan_workspace:

Visit http://your-server:6806 with your access code.

Importing from Notion

All four tools import Notion exports:

# 1. Export from Notion:
# Settings → Export → Markdown & CSV → Export All

# 2. For AppFlowy:
# Settings → Import → Notion → upload .zip

# 3. For AFFiNE:
# New workspace → Import → Notion

# 4. For Outline:
# Settings → Import → Notion

Decision Guide

Choose AppFlowy if:

You need a full Notion replacement (databases + docs + kanban + calendar views)
Your team is 1-50 people
You want a native desktop app (Flutter-based, fast)

Choose AFFiNE if:

You need a whiteboard + doc hybrid
You like local-first with optional sync
Design thinking and visual collaboration matter

Choose Outline if:

Primary use case is team knowledge base / wiki
You want the cleanest writing experience
Slack integration is important

Choose SiYuan if:

You want everything stored locally (single user or small team)
Offline-first is mandatory
You don't want a cloud sync component at all

Maintenance

# Update AppFlowy:
docker compose pull
docker compose up -d

# Backup AppFlowy PostgreSQL:
docker exec appflowy_postgres pg_dump -U appflowy appflowy \
  | gzip > appflowy-backup-$(date +%Y%m%d).sql.gz

# Backup AFFiNE:
docker exec affine_postgres pg_dump -U affine affine \
  | gzip > affine-backup-$(date +%Y%m%d).sql.gz
tar -czf affine-storage-$(date +%Y%m%d).tar.gz \
  $(docker volume inspect affine_affine_storage --format '{{.Mountpoint}}')

# Backup Outline:
docker exec outline-postgres-1 pg_dump -U outline outline \
  | gzip > outline-backup-$(date +%Y%m%d).sql.gz

Security Hardening and Backup Strategies for Self-Hosted Knowledge Bases

A knowledge base accumulates your organization's most valuable intellectual property — architecture decisions, product strategy, client notes, internal processes. This makes it a high-value target for both external attackers and internal data loss events. Treating your self-hosted knowledge base with the same security rigor as your production database is not paranoia — it's appropriate.

The first layer of protection is access control at the network level. Your wiki should not be accessible on a raw port to the public internet. Every deployment in this article should sit behind a reverse proxy (Caddy or Nginx) with TLS termination. Caddy is particularly convenient because it manages Let's Encrypt certificates automatically, so you get HTTPS for free with no certificate renewal management. Beyond TLS, consider whether your knowledge base needs to be internet-accessible at all. If your team is small and works from a fixed set of IPs or through a VPN, restricting access to your IP range eliminates the entire category of remote brute-force and credential stuffing attacks.

Authentication hardening differs by tool. Outline requires an external authentication provider — OIDC or SAML — which is actually a security advantage, because it means Outline itself never stores passwords. Configure Outline with your self-hosted identity provider (Authentik or Keycloak work well) and you inherit that provider's MFA enforcement, session management, and audit logging. AppFlowy Cloud uses GoTrue for authentication and supports email/password plus OAuth providers. Enable the email verification requirement during setup — without it, anyone who can reach your AppFlowy instance can create an account. AFFiNE's server mode similarly supports OIDC; the detailed comparison of Authentik vs Keycloak vs Authelia covers which identity provider fits best with this style of integration.

Backup strategy requires thinking through two failure modes: data corruption (database issue, failed migration) and complete data loss (server failure, accidental deletion). For data corruption, point-in-time recovery via PostgreSQL WAL archiving is the gold standard — it lets you roll back to any point in the past, not just to your last daily backup. For complete data loss, daily encrypted backups to an off-site location (Backblaze B2, Hetzner Object Storage, or an S3 bucket in a different region) provide the recovery path. Both mechanisms together give you comprehensive protection.

For AppFlowy, the critical data is the PostgreSQL database and the MinIO blob storage (uploaded files and images). A complete backup procedure backs up both. For Outline, the database plus the file storage volume contains everything. For AFFiNE, both the PostgreSQL database and the .affine/storage volume need to be backed up. Run these backups daily as cron jobs, verify them weekly by checking that the output files are non-zero and recent, and test a full restore to a separate server quarterly. The restore test is what separates a backup procedure that works from one that merely appears to work.

Integrating Your Knowledge Base with the Rest of Your Stack

A knowledge base is most useful when it connects to the other tools your team uses. Isolated documentation that requires manual updates and cross-referencing quickly falls out of date. The integrations available differ significantly between AppFlowy, AFFiNE, and Outline, and they influence which tool fits best in your specific environment.

Outline has the strongest integration story for teams already using chat tools. Its native Slack integration allows teams to search and preview Outline documents directly in Slack, link documents into conversations, and get notifications when documents are updated. There's a similar integration for Mattermost via webhook. For teams migrating from Slack as part of a broader OSS stack transition, this Mattermost-Outline pairing is compelling — your team communicates in Mattermost and documents in Outline, with seamless cross-referencing between them. The how to migrate from Slack to Mattermost guide covers setting up the webhook integrations that make this work.

Outline also has a direct Notion importer (upload the Notion ZIP export and Outline converts the Markdown files into its collection structure), making it the smoothest landing destination for teams migrating from Notion to a team-wiki-focused tool. The importer handles nested pages correctly, preserving your workspace hierarchy.

AppFlowy's integration surface is primarily through its API and the growing plugin system. For engineering teams, the ability to embed AppFlowy documents in CI/CD workflows — automatically updating a runbook when a deployment completes, or linking a post-incident review to the relevant infrastructure page — is possible through the API. The AppFlowy plugin ecosystem is still early compared to Notion's, but the core API is available for custom automation through tools like n8n.

AFFiNE's local-first architecture means its sync server primarily handles data synchronization rather than integrations. For teams that want their knowledge base to integrate deeply with external services, AFFiNE is currently the weakest option in this category. Its strength is the whiteboard-document hybrid experience and the local-first model where your data always exists on your devices regardless of server status.

Choosing the Right Tool Based on Team Size and Use Case

The decision matrix for these four tools depends on more than features — it depends on where your team's primary knowledge work happens and how much operational complexity you're willing to absorb.

For solo developers and writers, SiYuan or AFFiNE's local-first mode is the right starting point. Neither requires a server, your data is always local, and you can start using them immediately without any infrastructure decisions. The trade-off is that collaboration is limited without the sync server component. If you eventually add collaborators, the sync server can be deployed then — you're not locked into a different tool.

For small teams of two to fifteen people, AppFlowy Cloud or Outline are typically the best balance of capability and operational simplicity. AppFlowy provides the closest Notion-like experience with databases and multiple views. Outline provides the cleanest pure writing and documentation experience. If your team's primary Notion use was as a project management tool with database views, AppFlowy is the better migration target. If it was primarily a documentation and knowledge base tool, Outline is likely a better fit with lower operational overhead.

For larger teams with existing SSO infrastructure, Outline's OIDC integration and Authentik-compatible authentication make it the natural enterprise wiki choice. The BSL license is worth noting — it means Outline can't be used as the basis of a competing product, but for internal team use it imposes no restrictions. AppFlowy's AGPL license is a stronger open source guarantee if license purity matters to your organization.

The best open source note-taking and wiki tools comparison covers additional options including BookStack and Wiki.js for teams with specific requirements around structured hierarchical documentation or technical writing workflows. The right choice depends on your team's specific documentation patterns — there is no single winner across all use cases.

See all open source productivity and collaboration tools at OSSAlt.com/categories/productivity.

See open source alternatives to Notion on OSSAlt.

The SaaS-to-Self-Hosted Migration Guide (Free PDF)