Structurizr vs Mermaid vs PlantUML for C4 Diagrams

Jeff Bailey — Sun, 20 Sep 2026 00:00:00 +0000

Three tools draw C4 diagrams from text, and picking between them looks like a taste question about syntax. It is mostly a question about what you want to keep: a picture, or a model that can produce pictures.

Everything below was run on one system modeled three ways, with Structurizr 2026.09.19 (structurizr-* 6.2.3), Mermaid CLI 11.17.0 on mermaid 11.17.2, and PlantUML 1.2026.8 on Graphviz 16.1.0.

The short answer

Reach for Structurizr When the same system needs more than one diagram. You describe the model once and generate every view from it, so a renamed container changes in one place.

Reach for Mermaid When the diagram must render where it lives, in a README or a wiki, with no build step and no renderer to install.

Reach for PlantUML When layout quality matters most. Graphviz routes edges around boxes, and no other option here does.

These are not three competitors for one slot. Structurizr exports PlantUML and Mermaid, so the real choice is whether you keep a model upstream of whichever renderer you already use.

jq vs yq: Which One Should You Use?

Jeff Bailey — Sun, 20 Sep 2026 00:00:00 +0000

Both tools filter structured data with a similar language, so the question looks like a choice. It usually isn’t. jq reads JSON; yq reads YAML and four other formats, and writes them back with your comments intact. Most people end up with both installed.

This compares them where they actually differ: file formats, syntax compatibility, in-place editing, and speed. Everything below was run with jq 1.8.2 and yq v4.53.6 (the Go one) on the same files.

Jeff Bailey | Comparison

Structurizr vs Mermaid vs PlantUML for C4 Diagrams

The short answer

jq vs yq: Which One Should You Use?