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.

AFFiNE is an open-source workspace platform designed for people who want to combine note-taking, whiteboarding, planning, and knowledge management in one place. The README presents it as a local-first alternative to Notion and Miro, with emphasis on owning data on disk while still supporting cloud-based synchronization and collaboration. The project appears aimed at individuals and teams that need a flexible canvas for creative and structured work. It highlights an edgeless canvas where documents, tables, sticky notes, embedded web content, shapes, and slides can coexist, plus AI-assisted workflows for drafting reports, turning outlines into slides, summarizing content into mind maps, and prototyping ideas. It also mentions self-hosting and a plugin ecosystem, suggesting it is intended for users who want both a hosted product and the option to run and extend their own deployment.

Memos is an open-source, self-hosted note-taking application designed for quick capture and lightweight personal knowledge management. It is aimed at users who want a simple, timeline-first interface for creating Markdown notes without the overhead of folders or complex organization. The project emphasizes portability and self-hosting: notes are stored in Markdown, the app can be deployed with a single Go binary or via Docker, and it supports SQLite, MySQL, and PostgreSQL. It also presents itself as extensible through documented REST and gRPC APIs, making it suitable for integrations and custom workflows.

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.

Logseq is an open-source knowledge management and collaboration platform aimed at people who want a privacy-focused way to organize notes, tasks, and related information. It supports common note formats such as Markdown and Org-mode, and it emphasizes user control, longevity, and extensibility through plugins and themes. The README presents Logseq as suitable for students, professionals, and anyone managing personal or team knowledge workflows. It is available as a desktop application, has a web version for testing the DB version, and includes mobile apps. The DB version adds graph-based data, a new sync approach called RTC for real-time collaboration, and automated or SQLite database backup guidance because the feature set is still in beta/alpha.

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 in a deeply structured way. It presents notes as a hierarchical tree, supports cloning notes into multiple places, and includes tools for navigation, search, and advanced organization through note attributes and scripting. The project also provides a web interface, mobile access through a server installation, synchronization with a self-hosted sync server, and sharing/publishing notes to the public internet. It is designed for users who want a capable personal knowledge base system with rich editing, encryption, automation, and extensibility, while still being usable as a desktop app or via the browser.

Khoj is a personal AI application designed to extend a user’s capabilities as a "second brain." It combines conversational AI, document retrieval, semantic search, and agent creation so people can work with their own notes, files, and online information in one place. The project is aimed at individual users as well as teams and enterprises, with support for self-hosting, a cloud app, and enterprise deployment models. It can be used from multiple clients such as browsers, note-taking apps, desktop, mobile, and chat platforms, and it supports both local and online LLMs. The README emphasizes privacy and flexibility, highlighting that it can run on a personal computer or be accessed through the hosted service.

Open Notebook is a self-hosted, privacy-focused notebook application positioned as an alternative to Google NotebookLM. It is intended for people who want to keep research and source materials under their own control while still using modern AI workflows to organize, search, and transform information. The project supports a wide range of content types, including PDFs, videos, audio, web pages, and office documents, and it can work with many AI providers such as OpenAI, Anthropic, Ollama, and LM Studio. Users can create notebooks, search across their content, chat with context, and generate multi-speaker podcasts. The README emphasizes deployment flexibility, with Docker-based setup, local AI via Ollama, and a full REST API for automation.