How to optimize PDFs for render time in PDF.js?

[rjcorwin]

Hi all - We use PDF.js a lot on cheap $50 tablets in schools in the developing world. These tablets lack the processor power of most modern computers but we have noticed that some PDFs render faster than other PDFs. Does anyone know of a process for optimizing PDFs for faster load times in PDF.js?

[yurydelendik]

That's mostly a question for the mailing list at https://groups.google.com/forum/#!forum/mozilla.dev.pdf-js . However try the following:

1. Avoid using high resolution images -- 150 dpi resolution for scanned images shall be enough for screen and for low powered devices;
2. Try to use JPEG encoding for color images/photos in RGB colorspace when possible;
3. Avoid using expensive compositions/effects such as transitions/masking -- flatten transparency;
4. Avoid using PDF generators (or don't create content) that produce ineffective PDF output, e.g. LibreOffice creates a lots of tiny images for vector elements/pictures it does not understand;
5. If there is a setting, use web-optimized PDF output / linearization;
6. Fix or don't produce corrupted PDFs that does not conform PDF32000 specification.

Closing as answered.

[rjcorwin]

Thank you so much @yurydelendik !!