Mermaid JS

Mermaid is a JavaScript-based diagramming and charting tool that renders Markdown-inspired text definitions to create and modify diagrams dynamically, enabling developers to generate complex visual representations without leaving their code editor. Created by Knut Sveidqvist, the project won the 2019 JavaScript Open Source Award for the Most Exciting Use of Technology. The library supports a wide range of diagram types including flowcharts with subgraph clustering, sequence diagrams with participant grouping and activation bars, class diagrams following UML notation, state diagrams with composite states, entity relationship diagrams for database modeling, Gantt charts for project scheduling, pie charts for data proportions, journey maps for user experience flows, requirement diagrams, GitGraph for branch history visualization, mind maps, timeline diagrams, quadrant charts, and architecture diagrams. The text-based approach means diagrams are version-controllable in Git, reviewable in pull requests, and maintainable as living documentation that stays in sync with code. The Mermaid Live Editor at mermaid.live provides a browser-based playground with real-time preview, no account required, and direct sharing via URL. The Mermaid Advanced Editor at mermaid.ai adds AI-powered diagram generation from natural language descriptions, drag-and-drop visual editing, and voice input for hands-free diagram creation. Native integrations include GitHub which renders diagrams directly in README files and issues, GitLab, Notion, Obsidian, Jira, Confluence, Slack, Microsoft Teams, VS Code, and VuePress. The library is MIT licensed and actively maintained by hundreds of contributors. Copyright 2014-2026 Knut Sveidqvist.