Beauty Diagram
Guide

Render Mermaid diagrams online with live preview

Preview Mermaid diagrams online, check the rendered result, try themes, and export a cleaner SVG or PNG without splitting the workflow across separate tools.

Follow the workflow, open the example in the editor, then export or save the cleaner result.

At a glance

A guide for users searching for Mermaid live preview, Mermaid render online, or an online Mermaid editor that also beautifies the final output.

Paste Mermaid source and preview the renderUse pre-rendered examples for public pagesCompare themes before exportExport the confirmed result
Rendered proof
Mermaid live preview workflow from source to export.
Theme · Modern
Open this diagram in editor
Paste Mermaid sourceRender live previewShow readable diagramChoose themeExport SVG or PNG WRITER EDITOR PREVIEW EXPORT
View Mermaid sourcePlain-text diagram syntax — copy or edit directly.
diagram.mmd
1sequenceDiagram
2  actor Writer
3  participant Editor
4  participant Preview
5  participant Export
6  Writer->>Editor: Paste Mermaid source
7  Editor->>Preview: Render live preview
8  Preview-->>Writer: Show readable diagram
9  Writer->>Editor: Choose theme
10  Editor->>Export: Export SVG or PNG
Pre-rendered examples

Theme and animation variants

Rendered proof
Live preview workflow in Modern theme.
Theme · Modern
Open variant in editor
Paste Mermaid sourceRender live previewShow readable diagramChoose themeExport SVG or PNG WRITER EDITOR PREVIEW EXPORT
Rendered proof
The same preview workflow in Blueprint theme.
Theme · Blueprint
Open variant in editor
Paste Mermaid sourceRender live previewShow readable diagramChoose themeExport SVG or PNG Writer Editor Preview Export
Rendered proof
The same preview workflow in Slate theme.
Theme · Slate
Open variant in editor
Paste Mermaid sourceRender live previewShow readable diagramChoose themeExport SVG or PNG Writer Editor Preview Export

Paste Mermaid source and preview the render

Start with Mermaid source from a README, docs page, ticket, or prompt. The editor keeps the source visible while the rendered preview shows whether the diagram communicates clearly.

  • Flowcharts and sequence diagrams are the best first examples
  • Syntax stays editable after preview
  • The beautified output can be exported after review

Use pre-rendered examples for public pages

For public SEO pages, the rendered proof should be generated ahead of time or server-side. That keeps the page useful for crawlers and avoids relying on client-side Mermaid rendering for the first meaningful content.

Compare themes before export

A live preview is most useful when it supports decisions. Try a few themes against the same Mermaid source so the final export matches docs, decks, or architecture reviews.

Export the confirmed result

Once the preview is readable, export SVG for documentation or PNG for slides and tools that expect raster images.

Guide FAQ

Questions about this workflow

What is the difference between Mermaid preview and beautify?

Preview confirms that the source renders correctly. Beautify improves layout, hierarchy, theme, and export readiness.

Should SEO pages render Mermaid in the browser?

For important public pages, pre-rendered SVG or server-rendered output is safer because crawlers and users see proof immediately.

Can I use this as an online Mermaid editor?

Yes, as part of the broader Beauty Diagram editor that also supports PlantUML, draw.io import workflows, themes, and export.