8.4 Safari memory use

Hi Logan.

I’m passing on an issue report from our client - I erroneously didn’t have pdfJS express pinned to a particular version in our installation and production has automatically updated to 8.4. We’ll roll it back to 8.3 for now but here’s the report:

Which product are you using?
PDF.js Express Viewer

PDF.js Express Version

Detailed description of issue
“It is using a huge amount of memory on Safari on my dev machine, i.e. showing an alert every few minutes. and I’ve only seen those memory errors before on a 10 year old iPad mini.”

Expected behaviour
It will run on Safari without producing the alerts. I’ll ask Michelle for a screenshot of an alert.

Does your issue happen with every document, or just one?
I assume every document based on her report.

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I’ve tried to reproduce Michelle’s issue and am seeing other problems with UI 8.4.1 and core 8.4.0 - my Javascript console has:

webviewer-core.min.js:48 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading ‘call’)
at r (webviewer-core.min.js:48:348)

The PDF isn’t displayed. This is on Chrome Version 100.0.4896.127 (Official Build) (64-bit) on Linux.

Hey there,

We will investigate the memory usage issues - there was no core functionality changes between 8.3 and 8.4 so its a bit surprising to see this.

The errors you are seeing when upgrading are probably related to not upgrading properly - please make sure to completely wipe out the static assets and re-copy them over from the new version.

I’ll get back to you with my findings on the memory usage.

Also just as a test, would you be able to ask Michelle if she can reproduce that error playing around with WebViewer? Try clicking around here a bit in Safari and see if you get the same alert.


Hey again,

I tried investigating but I could not reproduce the problem. I tested PDF.js Express Viewer 8.4 on Safari with many different documents (some as large as 10,000 pages) and I didn’t have any memory issues. I suspect this is either document specific or device specific.

I will need more details or a better way to reproduce in order to help at the moment. If you could isolate the problem to a document or a set of documents that would be very useful too.


Thanks for the reply Logan.

I’m heading back from a conference in Portland, Oregon so might be a bit slow replying, but I’ll pass your reply on to Michelle and see if she can give you a reliable reproducible case.

I’m pretty sure the deployment process starts with just the package.json so don’t think there should be any stale files in there. I’ll double check and get back to you.



Logan, do you still have the document that we provided last year when we had issues?

Michelle says it’s the same document. We can provide it to you again if necessary.


If you could send it over again that would be great. I probably have it somewhere but I don’t remember what it’s called.