Open source diagrams projects
Every project in the registry tagged diagrams, ranked by real GitHub adoption.
Collaborative whiteboard with a hand-drawn aesthetic
Agent skill for beautiful, verifiable architecture, workflow, sequence, data-flow, and lifecycle diagrams—self-contained HTML with motion and crisp export.
Text-based diagramming that renders in code and docs
38 editorial diagram types for Claude Code, Codex, and Pi. Self-contained HTML + SVG. No shadows. No Mermaid slop.
D2 is a modern diagram scripting language that turns text to diagrams.
Generate production-quality SVG+PNG technical diagrams from natural language. 7 styles, UML support, and AI/Agent workflow patterns.
HedgeDoc - Ideas grow better together
Turn complex codebases into clear, navigable architecture diagrams with Claude Code.
Related tags
Frequently asked questions
How many open source diagrams projects are there?
This registry tracks 8 projects tagged diagrams, with 431,636 GitHub stars between them. The most-adopted is Excalidraw at 135,053 stars.
Are these diagrams projects free to use?
Yes — 8 of the 8 carry an explicit open-source licence across 4 distinct licences, so there is no licence fee. Where a project also sells a hosted or enterprise version, the self-hosted path remains free.
Which diagrams project should I choose?
The list above is ranked by GitHub stars, but stars measure attention rather than fit. Check three things on each card: the licence (permissive versus copyleft), the language it is written in, and the last-push date — a high-star project that has not been pushed in a year is a liability.
Are these diagrams projects still maintained?
7 of the 8 were pushed in the last 90 days, and every card shows its exact last-push date so you can see the rest. Sort your shortlist by that date before committing to a migration.