Draw C4 architecture diagrams online, level by level
The C4 model describes a system at four zoom levels. On Planloom you draw each level on its own canvas page with boxes, frames for system boundaries and labelled arrows, and keep them side by side with the code that implements them. It is a drawing canvas, not a C4 modelling DSL: there is no Structurizr-style model or automatic level generation.
What you get
One page per level
Keep context, container and component diagrams on separate pages of the same board.
Frames as boundaries
Draw the system boundary as a frame and move its contents together.
Rooted in the code
Link containers and components to repository paths and see which ones a merged pull request touched.
Present it
Walk the team through the levels in presentation mode.
How it works
- 1Open a free canvas and name three pages: Context, Containers, Components.
- 2Draw the people, systems and containers with labelled arrows.
- 3Link containers to their repository folders and share the board.
Questions
Is there a C4 palette or DSL?
No. You use the general shapes, frames and connectors. There is no C4 modelling language or generated views.
Can I keep the levels consistent?
Not automatically. Linking shapes to code paths helps you spot which ones changed.
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Open a canvas in seconds. No account, no credit card.