Be Converter

ASCII Art to UML Converter | Sketch Class Diagrams Online

Turn your rough ASCII class diagrams into polished Mermaid UML code instantly. Perfect for Sydney dev teams and Aussie devs needing quick diagrams.

This converter is optimised for simple ASCII art class diagrams with boxes, members, and arrows. Once converted, you can keep editing the Mermaid source and the preview will refresh automatically.

ASCII UML Input

Mermaid UML Output

Edit the generated Mermaid class diagram code directly. The preview below updates automatically after changes.

Mermaid UML Preview

Preview idle
The Mermaid UML preview will appear here after conversion.

Export Tools

Diagram Notes

Detected classes, relationships, and layout guidance will appear here after conversion.

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How to Convert ASCII Art to UML

Use this flow when you have a quick ASCII class sketch—like from a code review in Brisbane—and want a cleaner Mermaid UML version without doing it manually.

  1. 1

    Paste your ASCII class diagram

    Add a class-style ASCII sketch with box labels and members into the input panel.

  2. 2

    Pick a layout direction

    Leave it on Auto, or force left-to-right/top-to-bottom if your diagram has a clear reading order.

  3. 3

    Generate Mermaid UML

    Click Convert to UML to build the Mermaid class diagram code and render the preview in your browser.

  4. 4

    Edit and export the result

    Fine-tune the Mermaid source if you like, then copy it or download the .mmd, SVG, and JPEG files.

Why Use Our ASCII Art to UML Converter?

Built for a practical workflow: turn a quick text sketch into clean Mermaid UML, preview it on the spot, and export it for your docs or team updates.

Built for Class-Style Diagrams

It works best on box-based ASCII art representing classes and members rather than freeform drawings.

Editable Mermaid Output

Get a live Mermaid source code block instead of a static image, making it easy to refine and update.

Preview and Export in One Go

Generate code, check the rendered result, and export source, SVG, or JPEG files from the same page.

ASCII Art to UML FAQ

Common questions devs ask when turning text-based class sketches into Mermaid UML.

What kind of ASCII diagrams work best?
It performs best on box-based class sketches with clear names, attributes, and arrows. Complex ASCII art might need a bit of a tidy-up after conversion.
Can I keep editing the result?
Yes. The output is editable Mermaid source code, so you can keep refining the UML directly in the tool or your docs.
Is the preview live?
Yes. It renders in your browser using Mermaid.js, so the preview updates on the page as you edit the source.
Why might I need to fix the generated UML?
ASCII art doesn't always have perfect metadata. The converter is smart, but manual adjustments can help clarify the relationships and naming.
Can I save the result as an image?
Yes. Once rendered, you can download the diagram as SVG for high quality or JPEG for things like presentations.

About This ASCII to UML Converter

This tool is built for a specific purpose: converting an ASCII art class sketch into editable UML without redrawing everything from scratch. It uses Mermaid syntax because it's the standard for modern documentation workflows.

When to Use an ASCII Art to Mermaid Tool

This workflow is a lifesaver when you quickly sketch a class model in a Jira ticket, a markdown file, or a code review—like during a Melbourne meetup. Instead of leaving it as messy text, convert it to Mermaid UML for better readability.

Tips for Better ASCII to UML Output

  • Keep one class per box and put members on their own lines.
  • Use simple arrows so the relationships are easy to pick up.
  • Treat the output as a first draft and refine the names where needed.
  • Use SVG for docs and JPEG for sharing in chat or decks.
  • If the layout looks off, manually switch the direction before converting again.

Scope and Limitations

The page focuses on simple ASCII class-style diagrams and Mermaid UML. It doesn't try to handle every complex notation, which keeps the tool fast and reliable for the core use case.