Mermaidjs Syntax
Mermaid.js is a JavaScript-based diagramming tool that renders diagrams from text-based syntax, eliminating the need for separate graphical applications. The syntax uses a Markdown-inspired format designed for readability, allowing developers and documentation authors to embed diagram definitions directly into HTML, Markdown files, and documentation platforms. Mermaid processes these text definitions client-side in the browser, converting them into SVG diagrams dynamically.
Core Diagram Types
Mermaid supports multiple diagram types including flowcharts, sequence diagrams, class diagrams, state diagrams, entity relationship diagrams, Gantt charts, and pie charts. Each diagram type has its own syntax conventions, though they share common principles. Flowcharts use node declarations and arrow operators to define connections, while sequence diagrams describe interactions between actors using message syntax. The consistent approach across diagram types makes learning progressively easier as users become familiar with core patterns.
Mindmap and Advanced Features
Mermaid includes support for mindmap generation, a hierarchical diagram format useful for brainstorming and organizational visualization. Mindmaps are defined with indentation-based syntax that represents parent-child relationships. Beyond basic diagrams, Mermaid offers styling options, theming capabilities, and configuration settings that allow customization of colors, fonts, and visual properties without modifying the core diagram syntax.
Integration and Usage
Because Mermaid renders in the browser using JavaScript, integration is straightforward for web-based platforms. Many documentation tools including GitHub, GitLab, Notion, and Obsidian have native or plugin-based Mermaid support, allowing diagrams to be displayed directly without preprocessing. This approach maintains diagram definitions as human-readable text while providing visual output, making version control and collaborative editing practical.