What Is Mermaid (mermaid.js.org)?

Updated

Mermaid is a diagramming and charting tool that lets you create diagrams and visualizations using text and code instead of dragging shapes around a canvas. You write a short, readable syntax, and Mermaid renders it into a diagram. It suits developers, technical writers, and anyone who wants diagrams that live in plain text, version-control cleanly, and update by editing a few lines. Note that the project's site now points to a new home: "Mermaid.js now lives at mermaid.ai."

How Mermaid works

The core idea is text-to-diagram. You describe the structure you want, and the renderer handles layout, arrows, and styling.

  • Input: a text definition in Mermaid syntax (for example, a flowchart or sequence diagram).
  • Action: a Mermaid renderer parses that text and draws the diagram.
  • Result: a visual diagram you can embed in docs, READMEs, or web pages.

Because the source is text, changes are diffs rather than manual repositioning, which makes diagrams easier to review and maintain alongside code.

What you can create

Mermaid covers the diagram types most teams need for documentation and planning, including flowcharts and sequence diagrams. The site frames the tool around three qualities: it is easy to use, has integrations available, and is award winning. The exact catalog of diagram types is best confirmed on the current site, since the project has moved to mermaid.ai.

Who it's for

  • Developers who want diagrams in the same repo as their code.
  • Technical documentation authors who need diagrams that stay in sync with written content.
  • Teams that prefer reviewing diagram changes as text rather than as binary image files.

Getting started and getting involved

The site provides usage documentation, integration options, and community entry points. It also lists the people behind the project, including creator Knut Sveidqvist and a set of developers and sponsors, plus a contributors section. If you want to go further than using Mermaid, the community invites you to "Join the community and get involved!"

Key takeaway

Mermaid turns diagramming into a text-and-code task: write simple syntax, get a rendered diagram, and keep it maintainable. Start with the documentation and integrations on the current site, and check mermaid.ai for the latest home of the project.