Free online MERMAID to PDF converter

PDF is used when a Mermaid diagram must be shared with people who do not have a Mermaid editor, printed, or preserved in a fixed layout. Converting the source diagram to PDF renders its flowchart or mind map as a portable document rather than leaving it as editable diagram code.

What the MERMAID format is

Mermaid is a text-based diagram format used for flowcharts, mind maps, sequence diagrams, entity-relationship diagrams, timelines, and related visual documentation. Files commonly use .mmd or .mermaid; Mermaid code can also appear inside fenced blocks in Markdown files.

A Mermaid file contains source instructions such as node labels, connections, layout declarations, and styling rather than a finished image. Mermaid Live Editor, Mermaid CLI, Visual Studio Code extensions, Obsidian, and Markdown documentation systems can create or render these diagrams.

What the PDF format is

PDF stores the rendered diagram together with page dimensions, fonts, colors, and layout information. It is suitable for printing, email attachments, documentation, technical reports, and archival copies because recipients can view it with standard PDF software without installing Mermaid.

PDF is normally a presentation format, not a source format: editing the diagram usually requires changing the original Mermaid file and exporting a new PDF.

How to convert MERMAID to PDF

Using Mermaid CLI

1. Install Node.js if it is not already installed.
2. Install Mermaid CLI with npm install -g @mermaid-js/mermaid-cli.
3. Put the diagram source in a file such as flowchart.mmd. Ensure it starts with valid Mermaid syntax, for example flowchart TD.
4. Run mmdc -i flowchart.mmd -o flowchart.pdf.
5. Open flowchart.pdf and check labels, connectors, page breaks, and font rendering.

For a diagram that should fit within one PDF page, use mmdc -i flowchart.mmd -o flowchart.pdf --pdfFit. The command uses Mermaid’s Chromium-based renderer, so the PDF contains the rendered diagram rather than the original source code.

Using 101convert.com

You can convert the file on 101convert.com for free without installing software. Upload the Mermaid file, select PDF as the output format, start the conversion, and download the resulting document. This option is useful when Node.js and Mermaid CLI are unavailable.

Using a Mermaid editor

Open the source in an editor that supports Mermaid rendering, then use Export → PDF or the browser’s Print → Save as PDF. Browser printing is a fallback; it can include page margins, headers, footers, or scaling that are not present in a direct Mermaid CLI export.

Quality and compatibility considerations

Large diagrams may be scaled down until labels become difficult to read. Split a crowded source into several diagrams, increase the page dimensions through Mermaid CLI configuration, or export separate PDFs for different sections.

PDF output depends on the Mermaid version, rendering theme, installed fonts, and any referenced icons or external assets. Use the same Mermaid CLI version for repeatable exports, and choose a common font or embed required fonts through the renderer configuration when the PDF will be opened on other systems.

Interactive features, source-code editability, and some browser-specific styling do not carry over to PDF. Keep the original .mmd file alongside the PDF when future changes are likely.