(copied this from the other wix forum, as it perhaps makes more sense here)
I'm trying out the pdfviewer app and even if the element is large, the displayed info in the "display one page" is blurry. When you click it to open the pdf itself, it looks fine.
I'm wondering if this blurriness is due to html canvas stuff being used to render the pdf in the miniviewer - blurriness with 2dcanvas is not an uncommon issue. This article mentions some stuff with adjusting based on dpi - can you take a quick look in case it is useful for this issue? https://medium.com/wdstack/fixing-html5-2d-canvas-blur-8ebe27db07da
Maybe you're already tried to deal with it, but just wanted to be sure.
Also - I saw that you are actually using version 2.305 of pdfjs-dist from Feb 2018. Not sure if an upgrade would help or add some extra stuff as mentioned in this github issue for pdfjs: https://github.com/mozilla/pdf.js/issues/7041