Best open-source alternatives to Notion

AppFlowy is an open-source workspace application positioned as an alternative to Notion. It is designed for people who want a native, cross-platform productivity tool with stronger control over their data, and it also targets enterprises and builders who want to customize or extend the platform. The project combines Flutter and Rust to provide desktop and mobile clients, with self-hosting support for teams that want to run their own instance. The README highlights collaboration-oriented workplace management, AI capabilities, templates, databases, and documentation-style content, while emphasizing privacy, extensibility, and a community-driven approach to building productivity tools.

AFFiNE is an open-source workspace platform designed for writing, drawing, planning, and organizing knowledge in one place. It combines document editing and whiteboard-style canvas interactions, aiming to serve users who want a Notion- and Miro-like experience in a single product. The project emphasizes a local-first approach, so users keep data on their own devices while still getting real-time sync and collaboration across web and cross-platform clients. It also includes AI-assisted creation workflows, such as turning outlines into slides or summaries into mind maps, and supports self-hosting for teams or individuals who want more control over deployment and data.

Memos is an open-source, self-hosted note-taking application designed for fast, low-friction capture. It is aimed at users who want a simple place to write notes without managing folders, while still keeping data portable through Markdown storage and self-hosting on their own infrastructure. The project emphasizes simplicity and extensibility. It can be deployed with a single Go binary or via Docker, Docker Compose, Kubernetes, or source builds, and it supports SQLite, MySQL, and PostgreSQL. Memos also exposes REST and gRPC APIs for integration, includes zero telemetry, and is positioned as fully open software under the MIT license.

SiYuan is a personal knowledge management system designed around privacy and local control. It targets individuals who want to organize notes and knowledge using block-based editing, fine-grained references, and a Markdown-based WYSIWYG workflow rather than a traditional document-only model. The project emphasizes a broad feature set that includes large-document editing, databases, flashcards, export options, snippets, OCR, and an API for extension and integration. It also has a wider ecosystem of companion apps and components for mobile, desktop, marketplace content, and data repositories, suggesting it is aimed at users who want a cross-platform knowledge workspace with both local and deployment-oriented options.

Privacy-first graph-based knowledge management with bidirectional linking and outliner editing

Outline is a team knowledge base application whose source code is hosted in this repository. The README presents it as a collaborative product for organizing internal documentation, and it points users to a hosted version at getoutline.com for trying the service without self-hosting. The repository is mainly intended for people who want to run their own copy of Outline or contribute to development. The README directs operators to the hosting documentation for production setup and to a separate local-development guide for contributors. It also mentions debugging, testing, and database migrations, indicating that the project is a full-stack application with a server-side component and a frontend built around React and Node.js.

Trilium Notes is a cross-platform note-taking application aimed at people who want to organize large personal knowledge bases. It combines a desktop app, browser-based access through a server installation, and mobile web access, making it suitable for individual users who want both local use and self-hosted synchronization. The project emphasizes hierarchical organization, rich editing, and advanced note management features such as cloning, versioning, attributes, scripting, and visual maps. It also supports sharing notes publicly, importing and exporting content, and integrating with automation through a REST API. For more secure access, it includes OpenID and TOTP support, and it can be deployed on a self-hosted server or via Docker.

Wiki.js is an open source wiki application designed for creating and managing documentation sites. It is positioned as a modern, lightweight, and powerful solution built on Node.js, making it suitable for teams or individuals who want a self-hosted knowledge base or wiki platform. The README highlights official documentation, installation and requirements pages, and a live demo, indicating that the project is intended to be deployed and configured by users rather than used as a hosted SaaS product. It also points to community support channels, translations, and sponsorship information, suggesting an active ecosystem around the core wiki software.

Docmost is an open-source collaborative wiki and documentation platform aimed at teams that need a shared place to write, organize, and maintain knowledge. It combines wiki-style pages with documentation features and emphasizes real-time collaboration for multiple contributors working together. The project highlights spaces, permissions, groups, page history, search, file attachments, embeds, and diagram support, making it suitable for internal documentation, team knowledge bases, and structured collaboration. The README also points users to hosted cloud pricing and to self-hosting/development documentation, suggesting both managed and self-hosted usage paths.

BookStack is an opinionated documentation platform designed to help teams and individuals store, organize, and present knowledge in a simple, approachable way. The project emphasizes a clean out-of-the-box experience so new users can start creating content with only basic word-processing skills, while still offering more advanced features for power users. It is aimed at self-hosted deployments and is documented through the project website, which includes installation, administration, security, and development guidance. The README also points users to demo and support resources, indicating a mature community-oriented project. Its source is released under the MIT License, and the project explicitly positions itself as stable and easy to upgrade rather than highly extensible for unrelated use cases.