Free online flowchart and architecture diagrams
Introduction
draw.io (diagrams.net) is the most popular free diagramming tool: flowcharts, architecture, UML and network topologies all covered, integrating smoothly with VS Code and Confluence. Fully free with no feature walls, files local or cloud by choice — the safe pick for technical diagramming.
Key Features
- All-type diagram templates
- VS Code and Confluence integrations
- Local or cloud file storage
- Real-time collaboration (cloud mode)
- PNG/SVG/PDF/Visio exports
Pros
- Truly free with no gimmicks
- Offline-capable and private
Cons
- Weaker Chinese template ecosystem
Pricing
Completely free.（See official site for current pricing）
FAQ
Sharing .drawio files?
The file is JSON — commit it to repos for collaboration.
draw.io vs ProcessOn?
draw.io for free and engineering-grade; ProcessOn for templates and polish.
Gantt charts?
Basic shapes only; use dedicated tools for serious Gantt.
Related Sites
Collected on lucifer.city · Reviewed by the founder