How to Use Mermaid: The Ultimate Beginner’s Guide to Diagramming with Code

Are you looking for a simple way to create flowcharts, sequence diagrams, and Gantt charts directly from text? Mermaid is the perfect tool for developers, project managers, and technical writers who want to visualize ideas quickly and efficiently. In this step-by-step Mermaid tutorial, you’ll learn how to use Mermaid to generate beautiful diagrams with just a few lines of code.

What is Mermaid?

Mermaid is an open-source JavaScript-based diagramming and charting tool. It lets you create diagrams using a plain-text syntax, making it easy to integrate with Markdown, documentation, and wikis.

Getting Started with Mermaid

Install Mermaid: You can use Mermaid in your browser, with Markdown editors like VS Code, or embed it in your website. For web use, add the Mermaid CDN script:

<script type="module">
  import mermaid from "https://cdn.jsdelivr.net/npm/mermaid@10/dist/mermaid.esm.min.mjs";
  mermaid.initialize({ startOnLoad: true });
</script>

Write Your First Diagram: Use the following syntax in your Markdown or HTML:

```mermaid
graph TD
  A[Start] --> B{Decision}
  B -->|Yes| C[Do something]
  B -->|No| D[Do something else]

Render the Diagram: Save your file and view it in a Mermaid-compatible viewer or static site generator.

Why Use Mermaid?

Easy to learn: Simple, readable syntax.
Versatile: Supports flowcharts, sequence diagrams, class diagrams, and more.
Integrates anywhere: Works with Markdown, Notion, GitHub, and documentation tools.

Start using Mermaid today to turn your ideas into clear, professional diagrams—no design skills required!