Mermaid is an open-source, JavaScript-based diagramming and charting tool that renders text-based definitions into various types of visual diagrams. It allows users to create flowcharts, sequence diagrams, class diagrams, state diagrams, Gantt charts, pie charts, and more, using a simple, Markdown-inspired syntax. Instead of relying on visual editors, Mermaid interprets a textual description of a diagram and automatically generates the corresponding image.
Developed to simplify the process of creating and maintaining diagrams within documentation, Mermaid is often integrated into popular Markdown renderers, static site generators, and documentation platforms like GitHub, GitLab, MkDocs, and Confluence, enabling diagrams to be stored directly alongside code or text files in a version-control-friendly format. Its primary goal is to make documentation easier to create and update by making diagrams as code.