Mermaid Editor

Write Mermaid syntax, preview diagrams, and export SVG or PNG instantly.

What this tool does

Create flowcharts, sequence diagrams, and architecture diagrams from Mermaid text with live browser rendering.

Tool interface

Mermaid Input

Diagram rendering happens in your browser. Your Mermaid source is not uploaded.

Output

Preview

Render a diagram to see the preview.

Example input

flowchart TD
  A[Client] --> B[API Gateway]
  B --> C[Auth Service]
  B --> D[Data Service]
  D --> E[(Database)]

Example output

<svg><!-- Rendered Mermaid diagram markup --></svg>

Step-by-step instructions

  1. Paste Mermaid syntax or start from the example template.
  2. Click Render Diagram to generate the preview.
  3. Copy the SVG markup or download the diagram as SVG or PNG.

Common use cases

  • Debugging request payloads and encoded values quickly.
  • Generating development data and identifiers.
  • Validating text, URLs, timestamps, and structured content.

Useful for documentation, architecture reviews, and sharing system flows without opening design software.

Common mistakes to avoid

  • Treating decoded or formatted output as a security check when it is only a transformation.
  • Copying transformed values without confirming expected encoding or timestamp units.
  • Using sample data formats that differ from production payload structure.

Frequently Asked Questions

Is Mermaid data uploaded to a server?

No. Rendering happens in your browser and your diagram source stays local.

Can I download diagrams as images?

Yes. You can export SVG directly and also download PNG.

What input format does Mermaid Editor expect?

Use the format shown in the example input on this page.

What does Mermaid Editor output?

It returns transformed output you can copy or download as `diagram.svg`.

Why might Mermaid Editor return an error?

Most failures come from malformed input that does not match the expected format.

Does Mermaid Editor run in the browser?

Yes. Transformations are designed for in-browser usage so you can test and iterate quickly.

Can I copy or download results from Mermaid Editor?

Yes. You can copy the result or use the download action when file output is available.

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