Open Source Note Taking Apps
Notes are the longest-lived data most people have - years of ideas, research, and plans - which makes the storage format matter more than the editor. The open source apps below keep notes in formats you can read without the app that made them, mostly Markdown and plain files, and the ones that sync can do it through a server you run yourself instead of someone else's cloud.
AppFlowy
Open source AI workspace for projects, wikis, and teams with self-hosting and data control
AFFiNE
Local-first open-source workspace that merges docs, whiteboards, tables, and AI as a Notion and Miro alternative
Memos
Self-hosted Markdown note-taking timeline for quick notes, daily logs, links, and snippets
Joplin
Offline-first Markdown note and to-do app with encrypted sync across desktop and mobile
SiYuan
Privacy-first personal knowledge management with Markdown WYSIWYG, block references, and Docker hosting
Logseq
Privacy-first knowledge base for graph notes, Markdown, Org-mode, PDF annotation, and tasks
Outline
Team knowledge base and wiki with realtime collaboration, Markdown compatibility, and self-hosting documentation
Trilium Notes
Hierarchical note-taking app for large personal knowledge bases, with local use and self-hosted sync
Open Notebook
Open source, privacy-focused alternative to NotebookLM with local deployment and multi-model AI support