Online UML Diagram Tool

A focused UML diagram tool for developers and architects to model classes, interfaces, and relationships, then export scalable vector diagrams.

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1,256+

Total Calculations Run

< 15ms

Browser Execution Speed

100%

Client-Side Privacy

4.9 / 5.0

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About This Tool

A UML diagram tool processes a structured model of software elements to render diagrams that conform to UML 2.x conventions. Users supply nodes representing Classes, Interfaces, and Enums, and define relationships such as generalization, association, and composition. The tool translates this model into a vector diagram suitable for design reviews and documentation. The core workflow normalizes inputs, computes an aesthetically balanced layout using a layered algorithm, and renders shapes and connectors with consistent styling. It supports multiple export formats (SVG, PlantUML, Mermaid) to fit different design pipelines and knowledge bases. Target audiences include software architects, developers, educators, and product teams who need fast, repeatable visuals. Unique value lies in UML-2.x conformance, template reuse, and multi-format exports that streamline design reviews and onboarding.

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How to Use

Provide inputs: define nodes (id, type: Class/Interface/Enum) and relationships (from, to, type).
Validate inputs: ensure IDs exist and relationship types are allowed.
Choose layout/export: select auto-layout and output formats (SVG, PlantUML, Mermaid).
Run generation: compute positions and render the diagram.
Review outputs: assess the diagram, adjust inputs if needed, and re-run.

Frequently Asked Questions

Find Quick Answers

What diagrams can I create?

You can model Classes, Interfaces, and Enums, with relationships such as Generalization, Association, Aggregation, Composition, and Dependency. The tool adheres to UML 2.x notations and common design conventions.

Which exports are supported?

SVG is produced natively; PlantUML and Mermaid textual exports are available for editing in external tools; PNG export may be offered for raster workflows. Styling is retained in SVG outputs.

Can I reuse templates?

Yes, you can save and apply diagram templates that preset element styles, relationship defaults, and layout rules to ensure consistency across projects.

Is auto-layout available?

Auto-layout uses a layered algorithm to position elements and reduce cross-overs. Users can adjust node sizes and constraints to improve readability.

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