Diagram Design: 29 editorial diagram types for Claude Code

What is Diagram Design?

When working with AI coding assistants like Claude Code, creating diagrams often runs into a problem: tools like Mermaid produce “industrial-looking” outputs that lack editorial polish. The diagram-design repository by cathrynlavery has climbed to #1 on GitHub Trending with over 17,200 stars, solving this exact problem.

Diagram Design provides 29 editorial diagram types as self-contained HTML + SVG files. No external dependencies, no Mermaid, and notably: no shadows — maintaining the clean, professional aesthetic of editorial design.

Why diagram-design went viral

The problem with Mermaid and existing tools

Mermaid is the most popular tool for generating diagrams from text. However, Mermaid’s output has several limitations:

• Industrial look: Default fonts, muted colors, rigid layouts
• Hard to customize: Changing styles requires complex CSS overrides
• Runtime dependency: Needs JavaScript rendering, doesn’t work in static environments
• “Mermaid-slop”: The term the repo author uses for Mermaid’s unsophisticated output

The diagram-design solution

Instead of generating from text, diagram-design provides complete HTML + SVG templates:

• Each diagram is a standalone HTML file, viewable immediately in any browser
• Inline SVG — no JavaScript needed, no CDN required
• Consistent style: clear typography, refined colors, balanced layouts
• Easy to copy-paste into Claude Code prompts for AI customization

The 29 diagram types

The collection covers nearly all illustration needs in technical and business documentation:

Architecture diagrams

• System architecture: Display system components and connections
• Data flow: Visualize data flow from source to destination
• Deployment diagram: Infrastructure deployment layouts

Process diagrams

• Process flow: Steps in a business process
• Decision tree: Decision trees with yes/no branches
• Timeline: Event timelines

Organization and relationship diagrams

• Org chart: Company organization charts
• Relationship map: Entity relationship maps
• Hierarchy: Hierarchical structures

Comparison and analysis diagrams

• Comparison matrix: Feature comparison matrices
• SWOT analysis: Strengths, weaknesses, opportunities, threats analysis
• Venn diagram: Set intersection Venn diagrams

Special diagrams

• User journey: User journey maps
• State machine: State machines
• Sequence diagram: Interaction sequence diagrams

Practical applications

In development workflow

When working with Claude Code, developers can:

1. Select the appropriate template from the 29 types
2. Paste it into the prompt along with a request: “Create an architecture diagram for my microservices application”
3. Claude Code generates a complete HTML file
4. Open in browser to view, or export as SVG to embed in documentation

In technical documentation

Technical writers use diagram-design to:

• Create consistent illustrations across all documentation
• No need to learn complex design tools
• Lightweight output, fast loading, responsive on all devices

In presentations

Business analysts use it to:

• Create slides illustrating business processes
• Export high-quality SVG for PowerPoint/Keynote
• Quickly update when processes change

Comparison with other solutions

Criteria	Mermaid	diagram-design	Draw.io
JS dependency	Yes	No	Yes
Default style	Industrial	Refined editorial	Basic
AI integration	Difficult	Natural (HTML)	None
Self-contained	No	Yes	No
Template count	Unlimited (generated)	29 (curated)	Hundreds

diagram-design’s strength isn’t quantity but curation quality — each template is carefully designed to ensure output is always beautiful and professional.

Why “no shadows”?

The author emphasizes “no shadows” as a design philosophy. In editorial design — the style of high-quality magazines and newspapers — shadow effects are avoided because:

• Flatness: Makes information stand out without distraction
• Print: Shadows render poorly on printed paper
• Accessibility: Visually impaired users can read flat content more easily
• Professionalism: Minimalist style conveys professionalism

Repository structure

diagram-design/
├── templates/
│   ├── system-architecture.html
│   ├── data-flow.html
│   ├── process-flow.html
│   ├── org-chart.html
│   └── ... (29 files)
├── examples/
│   └── ... (usage examples)
├── README.md
└── LICENSE

Each HTML file in templates/ is completely standalone — no imports, no dependencies, just double-click to open.

Conclusion

Diagram-design represents an interesting philosophy: instead of trying to build a perfect diagram generation tool, provide high-quality templates that AI can customize. In the era of AI coding assistants, this approach is far more practical than building complex DSLs.

With 17,200+ stars on GitHub, the community has spoken: developers need diagrams that are beautiful, fast, and easy to integrate with AI workflows — not another complex tool.

The repo on GitHub: github.com/cathrynlavery/diagram-design