Zooming in complex PDFs with many layers is slow / unresponsive

WebViewer Version: 8.10.0

Do you have an issue with a specific file(s)?
Complex PDFs with many layers.

Can you reproduce using one of our samples or online demos?

Are you using the WebViewer server?

Does the issue only happen on certain browsers?

Is your issue related to a front-end framework?

Is your issue related to annotations?
Not sure

Please give a brief summary of your issue:
Zooming in complex PDFs with many layers is slow

Please describe your issue and provide steps to reproduce it:
Zooming in and out of documents with many layers is slow and freezes for a few secs

Please provide a link to a minimal sample where the issue is reproducible:

Hi Apryse Team,

we have complex PDF manuals with many layers in it, which makes the zooming in / out slow and unresponsive for a few secs afterwards. I’ve tried to check what makes our PDF slow in Webviewer and the only thing I found via Adobe is that it has really many layers for all the texts.

Is that something which can make zooming slow?

I’ve checked other PDF readers (i.e. PDF.js) and those are better here, as they seem to postpone rendering all until the zoom is completed. In Webviewer what I can see is the page gets rendered even mid-zooming which causes high spikes in CPU usage.

Could you help us how we could make zooming more performant on simply using the webviewer frontend?

Hello @balazs.vajdics,

There are a couple of things you could try on your end. First I would see if changing the cache and pre-rendering parameters improve performance for your doc:

If these do not help, you could also try optimizing your document for web viewing.

If this does not help, we are also happy to have a look at the file in question. You can send in a ticket via our freshdesk portal to share this file if you do not want to share it via this forum.

Best Regards,
Armando Bollain
Software Developer
Apryse Software Inc.

Hi @Armando_Bollain,

thanks for the suggestions, I’ve tried playing around with the parameters, but it did not seem to change the zooming slowness.

I’ve created a support ticket, as we can’t share the pdf publicly, but will update this topic with the findings from there later on.

Best regards,
Balazs Vajdics