Free C4 Architecture Diagram Maker Online
Free C4 Architecture Diagram Maker Online
Visualize software architecture at multiple levels with the C4 model — context, containers, and components.
What is a C4 Diagram?
A C4 diagram uses the C4 model to visualize software architecture at different levels of abstraction. C4 stands for Context, Container, Component, and Code. Context diagrams show how a system fits into the world, Container diagrams show the high-level technology choices, and Component diagrams show the internal structure of containers.
Common Use Cases
- •Architecture documentation - Show system design at multiple abstraction levels
- •System context - Visualize how your system interacts with users and external systems
- •Container architecture - Document deployment units and their communication
- •Component design - Show internal structure of services and applications
- •Technical communication - Share architecture with stakeholders at appropriate detail levels
Syntax Quick Reference
| Element | Syntax | Description |
|---|---|---|
| Person | Person(id, "Name", "Desc") | A user of the system |
| System | System(id, "Name", "Desc") | Your software system |
| External system | System_Ext(id, "Name") | Third-party system |
| Relationship | Rel(from, to, "Label") | Connection between elements |
| Container | Container(id, "Name", "Tech") | Deployment unit (in C4Container) |
| Boundary | System_Boundary(id, "Label") { } | Group related elements |
Export Options
PNG Export
High-resolution images for documents and presentations.
SVG Export
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PDF Export
Print-ready format for professional documentation.
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