Very nice! I once had a side project with a built-in PDF viewer. My first version used pdf.js, but when zooming in quickly, it felt sluggish and hard to keep the zoom focus in the right place.

So I built my own PDF viewer, this time using pdfium in C++ with Metal for rendering — here’s a quick demo: https://youtu.be/jJMhVn5yzEI

I implemented a tiling technique to balance memory usage and performance. I didn’t realize pdfium could be so performant in WebAssembly — and honestly, I actually prefer developing UI on the web compared to C++.

Seems to work great!

Little note: when you switch from redaction to view with the redaction tool (red lines) active it stays active in the view mode. Impossible to scroll because it still redacts.

Refresh fixes it.

Do I understand correctly - the repo contains a copy of Google’s pdfium.js along with a UI and lots of abstraction layers/examples for various JavaScript frameworks?

(Not a JavaScript developer.)

I tried a random PDF that includes an annotation, but the annotation didn't show up. I assume the annotations this supports are no real annotations?