Modern Mermaid – Online flowchart and diagram editor with live preview

Summary: Modern Mermaid is a free online diagram editor that supports flowcharts, sequence diagrams, class diagrams, ER diagrams, and Gantt charts. It offers live preview, multiple themes, annotations, and export options for consistent visuals.

What it does

It allows users to write diagrams as code with instant live preview and export clean visuals for documentation, blogs, and presentations.

Who it's for

Designed for developers, product managers, and indie hackers needing fast, code-based diagram creation without complex UI tools.

Why it matters

It solves the problem of switching between multiple diagram tools by providing a unified, developer-friendly editor with consistent styling and live feedback.