Mermaid.js
Mermaid is an award-winning, open-source JavaScript library for creating diagrams and charts from text-based definitions. Founded by Knut Sveidqvist, Mermaid allows users to generate complex visualizations using a simple, Markdown-inspired syntax — no manual drawing required.
Overview
Mermaid enables developers, technical writers, and teams to create flowcharts, sequence diagrams, Gantt charts, class diagrams, state diagrams, pie charts, and many other diagram types directly from text. The diagrams are rendered dynamically in the browser, making them easy to embed in documentation, wikis, and web applications.
Key Highlights
- Text-to-Diagram: Write simple text syntax and Mermaid automatically generates professional diagrams
- Open Source: Fully open-source project with an active community of contributors
- Award-Winning: Won the 2019 JavaScript Open Source Award for "The Most Exciting Use of Technology"
- Live Editor: Access the interactive Mermaid Live Editor at mermaid.live for instant diagram creation
- Wide Integration: Compatible with numerous platforms and applications including GitHub, GitLab, Notion, Confluence, and many more
- Version 11.14.0: Continuously updated with new features and diagram types
Community & Team
Mermaid is maintained by a dedicated team of developers led by creator Knut Sveidqvist, with contributions from a global open-source community. The project has recently transitioned to mermaid.ai as its new home, consolidating the open-source library and the platform built around it.
Target Audience
Developers, technical writers, project managers, software architects, and teams who need to create diagrams as part of their documentation workflow
Key Features
- Text-based diagram syntax
- Flowchart creation
- Sequence diagrams
- Gantt charts
- Class diagrams
- State diagrams
- Pie charts
- Live editor (mermaid.live)
- GitHub/GitLab integration
- Markdown compatibility
- SVG output
- Theme customization
- Open-source and free
Use Cases
- Technical documentation
- Software architecture visualization
- Project planning with Gantt charts
- API documentation with sequence diagrams
- Database schema visualization
- Workflow documentation
- README files on GitHub
- Wiki and knowledge base diagrams
- Presentations and reports
- Educational materials
Pros
- Free and open-source
- Easy to learn text-based syntax
- No manual drawing required
- Version-controllable diagrams
- Wide platform integrations
- Active community and regular updates
- Award-winning technology
Cons
- Requires learning Mermaid syntax
- Limited customization compared to GUI tools
- Complex diagrams can be hard to express in text
- Rendering may vary across platforms
Pricing
Free and open-source under MIT license
