Best Open-Source Note-Taking Apps in 2026
From local-first Markdown to block-based knowledge bases — the strongest open-source note-taking apps and how they differ.
Three families of note-taking apps
Open-source note apps cluster into three families: local-first Markdown editors that keep files on disk, block-based knowledge graphs that model notes as connected entities, and outliner-style apps built on bullet hierarchies. Each family optimizes for a different workflow.
The mistake is picking the app your friend uses. Pick the family that matches how you think.
Local-first Markdown
These apps store notes as plain .md files, giving you full ownership and portability. They shine for portability and interoperability with other tools. Look for active update cadence and healthy issue ratio when comparing them.
Block-based knowledge graphs
Apps like Logseq and SiYuan model notes as interconnected blocks rather than flat files, enabling backlinks and graph navigation. They trade some simplicity for knowledge-structure power. Both are strong open-source options that rank well on the recommendation score thanks to active communities.
Choosing by data, not hype
Search 'note taking app markdown' or 'block based knowledge base' and look at the activity and health dimensions of the score. A note-taking app is something you live in for years — pick one that is actually maintained.