A guide to converting HTML elements into downloadable SVG images using JavaScript libraries for use in documentation, books, and presentations.

The Problem

When creating documentation, books, or presentations, you often need visual representations of CSS layouts that work across HTML, EPUB, and PDF formats. Traditional screenshots have limitations - they're raster images that don't scale well and can't be easily edited. SVG provides a vector-based alternative.

Two JavaScript Libraries for HTML-to-SVG Conversion

Satori

Uses JSX to produce SVG images. While useful for certain applications, it's less ideal for capturing existing DOM layouts.

html-to-svg

Converts DOM nodes directly to SVG images. This library proves more effective for capturing CSS layout demonstrations and live HTML elements.

Practical Implementation

The solution creates a web page containing multiple SVG screenshots with interactive controls.

HTML Structure

Each CSS layout demo is contained in a section:

<h2><code>box-sizing</code></h2>
<section id="css-box-sizing">
  <style>
    .outer {
      ...
    }
  </style>
  <div class="outer">
    ...
  </div>
</section>

JavaScript Processing

The implementation iterates over sections and adds interactive <details> elements that provide:

Download Links: A link labeled "Download css-box-sizing.svg" that triggers browser download of the SVG file

Preview Capability: Expandable details showing the generated SVG image for comparison with the original HTML

Smart Filename Generation: SVG filenames derived from section IDs for organized file management

Download Mechanism

The download functionality uses the Blob API and object URLs:

const fileBlob = new Blob(
  [svgElement.outerHTML], { type: 'text/plain' }
);
link.href = URL.createObjectURL(fileBlob);

The browser uses the filename specified in the download attribute of the link, creating a seamless download experience without server-side processing.

Benefits

Scalability: Vector-based SVG images scale perfectly at any resolution

Editability: SVG files can be edited as text or in vector graphics applications

Multi-format Support: Works across HTML, EPUB, and PDF formats

Interactive Comparison: Users can compare original HTML with generated SVG

Automated Workflow: JavaScript automation enables batch processing of multiple layouts

Use Cases

• Technical documentation with visual CSS examples
• Educational materials demonstrating web layouts
• Books and ebooks requiring scalable diagrams
• Presentation slides with interactive web components
• Design system documentation with component previews

Conclusion

Converting HTML elements to SVG screenshots provides a flexible, scalable solution for documenting web layouts. The html-to-svg library combined with browser download APIs creates an efficient workflow for generating high-quality visual documentation that works across multiple publishing formats.