C4-PlantUML
Leading#7 in Open sourcemedium confidence
The standard way to render C4-model software architecture diagrams as code (~7.4k★) — the go-to for C4 + text.Our read
Why it ranks #7
The de-facto C4 extension for PlantUML at ~7.4k GitHub stars, with dedicated macros and examples for every C4 level; it ranks below general tools because its scope is intentionally architecture-model specific.Here is the catch
requires PlantUML and its Java/server toolchain
narrower use case than general diagramming libraries
layout macros and version compatibility can require manual tuning
Does this well
well-established text workflow for teams already using the C4 model
consistent notation across multiple architecture abstraction levels
inherits PlantUML's rendering and integration ecosystem
Pricing
Checked by hand on 2026-07-23. Prices in this category change often — if this looks wrong, it probably is.
Key features
C4 context, container and component diagramsdynamic, deployment and sequence viewslayout macros, tags and custom stylingVS Code snippets and PlantUML compatibility
Sources we read
Quick facts
More in this area
The rest of the Open source column.- 1MermaidThe de-facto text-to-diagram standard (~89.4k★) — natively rendered in GitHub/GitLab Markdown, making it the default diagram-as-code format agents produce for architecture, flow and sequence diagrams.
- 2ExcalidrawThe dominant open-source virtual whiteboard (~128.3k★) — hand-drawn aesthetic, hugely used for freeform architecture sketches and system diagrams.
- 3Diagrams (mingrammer)The leading diagram-as-code library for cloud/system architecture (~42.5k★) — draw AWS/GCP/Azure/Kubernetes architecture from Python.
- 4D2Fast-rising modern diagram scripting language (~24.8k★) — cleaner syntax than PlantUML with strong automatic layout.
- 5tldrawInfinite-canvas whiteboard SDK (~49.2k★) — the toolkit developers build collaborative diagramming apps on.
- 6PlantUMLThe long-standing text-to-UML workhorse (~13.2k★) — most complete UML coverage, ubiquitous in enterprise toolchains despite dated visuals.