C4 Architecture Diagrams,
Simplified
Design system architecture with interactive, hierarchical diagrams. Auto-layout, drill-down navigation, and real-time visualization — all in the browser, no signup required.
Hierarchical C4 Modeling
Context, Container, Component, and Code levels — drill into any layer of your system with a single click.
Auto Layout & Routing
Dagre-powered hierarchical layout with orthogonal edge routing. Your diagrams stay clean automatically.
Views & Visualization
Toggle depth coloring, entry/exit points, and connectivity overlays to surface architectural insights.
Collapse & Expand
Collapse containers to see the big picture, expand them to inspect internals. Implied edges are inferred automatically.
Undo / Redo & History
Full history tracking across every operation. Experiment freely, roll back instantly.
Client-Side & Private
Everything runs in your browser. No accounts, no servers, no data leaves your machine.
What is C4?
The C4 model is a hierarchical approach to software architecture diagramming created by Simon Brown. It organizes system design into four zoom levels — Context, Containers, Components, and Code — so you can communicate architecture at the right level of detail for your audience. Levels makes it fast to build and explore C4 diagrams interactively.