u/topdna

I built a pure browser PPTX viewer with high-fidelity PDF export. Looking for real-world deck feedback.

Hi everyone,

I’m building a browser-based PPTX viewer and I’m looking for honest feedback from
people who work with real PowerPoint files.

Demo:
https://ningyum.github.io/viewer-examples/

The key point: It runs entirely in the browser. It does not require PowerPoint, Office,
LibreOffice, a server-side conversion service, or uploading the deck to a backend. It
can also export the deck to a high-fidelity PDF.

The goal is not to replace PowerPoint editing. It’s to make “open this .pptx in a web
app” look much closer to PowerPoint than typical PPTX-to-HTML viewers.

Current focus:

- Pure browser-side preview
- High-fidelity PDF export
- Text, shapes, images, tables, and common layouts
- Theme / master / layout inheritance
- Charts: bar, column, line, area, pie, doughnut, scatter, radar, bubble, etc.
- Math / equation rendering
- EMF / WMF vector image support
- SmartArt fallback rendering
- Speaker notes / presenter mode
- Hyperlinks, slide actions, media preview, and basic transitions / animations

It is not a full Office clone. Known hard areas are still full SmartArt layout fidelity,
3D charts/effects, long-tail OOXML features, and complex PowerPoint animation behavior.

By the way, it is very lightweight. The preview-only bundle is under 2 MB, and the PDF export module is also under 2 MB and loaded lazily.

I’d really appreciate feedback on:

  1. Does the demo look close enough to PowerPoint for normal viewing?
  2. What kinds of slides break first?
  3. Are charts, fonts, equations, SmartArt, or old templates visibly wrong?
  4. If you use PowerPoint professionally, what would make this unusable for you?

I’m the developer of this viewer. Any feedback is welcome.

reddit.com
u/topdna — 5 days ago