About

Introduction

html2pptx-pro is a library that converts HTML elements to PowerPoint presentations using the pptxgenjs library. It traverses the DOM, parses CSS styles, and renders the result as PPTX slides -- preserving backgrounds, borders, text styling, lists, and layout structure.

How it works

The library follows a multi-stage pipeline:

1. DOM cloning -- The target element is cloned into an isolated iframe to avoid modifying the original page.
2. DOM normalization -- Animations are disabled and transforms are reset to ensure a stable snapshot.
3. DOM parsing -- The cloned DOM tree is parsed into an internal ElementContainer tree structure.
4. CSS parsing -- Computed styles are parsed through 50+ CSS property descriptors.
5. Stacking context construction -- Elements are ordered according to the CSS painting order (7 layers).
6. PPTX rendering -- The tree is rendered to PowerPoint shapes via pptxgenjs, converting CSS pixels to inches.

Limitations

html2pptx-pro builds a PPTX representation from DOM and CSS information. Because PowerPoint has different capabilities than a browser, some CSS features cannot be faithfully represented:

• Radial gradients
• URL background images
• opacity blending
• CSS filter effects
• SVG and Canvas element rendering
• CSS transforms in PPTX output
• mix-blend-mode

For a full list of supported CSS properties, see the features page.

Browser compatibility

The library works in modern browsers that support:

• ES2015+ (Promises, async/await)
• getComputedStyle
• Canvas API (used internally during processing)

Supported browsers:

• Chrome 60+
• Firefox 55+
• Safari 12+
• Edge 79+