UML Diagram Tool

Create professional UML diagrams instantly with this free online tool. Supports class diagrams, sequence diagrams, and more with real-time preview.

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About This Tool

This UML Maker Online tool allows you to create professional Unified Modeling Language (UML) diagrams directly in your browser. Using Mermaid.js syntax, you can generate class diagrams, sequence diagrams, use case diagrams, activity diagrams, and state diagrams. The tool features a real-time preview, customizable styling options, and multiple export formats including PNG, SVG, and PDF. Perfect for software developers, system architects, and students who need to visualize software designs quickly and efficiently.

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How to Use

Select your diagram type from the dropdown menu
Enter your UML code using Mermaid.js syntax in the text area
Customize styling options like theme, font size, and background
Click 'Generate Diagram' to see a real-time preview
Use the export buttons to download your diagram as PNG, SVG, or PDF
For beginners, use the example templates to get started quickly

Frequently Asked Questions

Find Quick Answers

What UML diagram types are supported?

The tool supports class diagrams, sequence diagrams, use case diagrams, activity diagrams, state diagrams, and entity relationship diagrams using Mermaid.js syntax.

Do I need to install any software?

No, this is a completely web-based tool that runs in your browser. No downloads or installations are required.

Can I save my diagrams?

Yes, you can export your diagrams as PNG, SVG, or PDF files to save them locally to your device.

Is there a syntax guide available?

Yes, the tool includes example templates for each diagram type to help you get started. You can also refer to the official Mermaid.js documentation for complete syntax details.

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