Creating Beautiful Diagrams with Mermaid

Mermaid lets you create diagrams and visualizations using a simple text-based syntax directly in your Markdown files. No more switching between tools or embedding static images — your diagrams live alongside your documentation and can be version-controlled.

Why Mermaid?

Traditional diagram tools require separate files, expensive licenses, or cloud services. Mermaid diagrams are:

• Text-based — version control friendly
• Portable — render anywhere Mermaid is supported
• Maintainable — update diagrams by editing text
• Fast — no GUI needed

Flowcharts

The most common diagram type. Use graph or flowchart to define direction:

flowchart LR
    A[Start] --> B{Decision}
    B -->|Yes| C[Do something]
    B -->|No| D[Do something else]
    C --> E[End]
    D --> E

Direction options: LR (left-right), RL, TB (top-bottom), BT.

Sequence Diagrams

Perfect for documenting API calls and system interactions:

sequenceDiagram
    User->>Server: GET /api/posts
    Server->>Database: SELECT * FROM posts
    Database-->>Server: rows[]
    Server-->>User: JSON response

Gantt Charts

Visualize project timelines:

gantt
    title Project Timeline
    dateFormat  YYYY-MM-DD
    section Design
    Wireframes    :2024-01-01, 7d
    Mockups       :7d
    section Development
    Frontend      :2024-01-15, 14d
    Backend       :2024-01-20, 10d

Class Diagrams

Document object-oriented designs:

classDiagram
    Animal <|-- Dog
    Animal <|-- Cat
    Animal : +String name
    Animal : +makeSound()
    Dog : +fetch()
    Cat : +purr()

Tips

• Use %% for comments in your diagrams
• Keep diagrams focused — one concept per diagram
• Test your syntax at the Mermaid Live Editor before embedding