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How to disable PDF.js built in viewer for my site


On my site PDF files are used for printing purposes. Starting with v19 visitors start start to claim that this functionality is not working any more. The cause of this is the new built in PDF viewer. It doesn't open print dialog after pdf file download if the the file is built to doing this. Also I’ve found that the quality of printing via the built in viewer is unacceptable. The content is distorted by the JPEG compression and additional headers and footers are present on the page. So for my site built in PDF viewer should be disabled at all. I've found no way to do this at the site level. I think that the instructions for disabling the new feature is too complex for ordinary users and it easier to ask them to use another browser. I think that should be an option at the site level to disable the built in PDF viewer. At least this option should force the browser to ask the user that for working properly with this site the built in PDF viewer should be disabled. And if user choose to disable it this should be done in one click.

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  • User Agent: Opera/9.80 (Windows NT 6.1; WOW64; U; en) Presto/2.10.229 Version/11.62

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Tyler Downer
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1166 solutions 6653 answers

Websites can't disable PDF.js, and they never will be able to. The security implications of allowing a website to modify preferences in a browser, set plugins, etc. are immense! Instead, what you can do, is if there are specific issues with your website and PDF.js, please go to bugzilla.mozilla.org, and file a bug report to get them fixed.

Ironchew 0 solutions 1 answers

You can completely disable pdf.js by going to "about:config" and setting "pdfjs.disabled" to true.

Edit: Reading your post again, I do agree that sites should be able to suggest that Firefox not use the built-in PDF viewer, but I don't know if Firefox has this functionality.

Modified by Ironchew

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Yes Firefox is as always highly customisable, so users may choose instead to

  • download the file to view in a standalone Word Processor or PDF Reader
  • OR open using an alternative PDF viewing plugin.

We document this (and the process to change this was mentioned in a post above)

Question owner

Unfortunately there is no way to specify particular plug-in by author of the site even optionally. And the critical functionality has stopped working after some users upgraded their browsers. So i have another question Is there way to check in javascript code if built in PDF.js viewer is disabled

piotrnm 0 solutions 2 answers

Helpful Reply

This PDF.js has crap quality of printing.

Tyler Downer
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1166 solutions 6653 answers

For anyone having trouble with PDF.js, please try firefox beta, there are some improvements to PDF.js (especially printing) that may make your life easier with it.

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The latest version of the PDF viewer is available as an extension and does a better job than the 0.6.143 version shipped with Firefox 19 in a lot of cases.

You can find the latest version of the PDF Viewer (pdfjs) extension here:

rsbrux 0 solutions 6 answers

Helpful Reply

@john99, FF19 ignores your "Application preferences", described in [https://support.mozilla.org/en-US/kb/change-firefox-behavior-when-open-fi...] and [https://support.mozilla.org/en-US/kb/view-pdf-files-firefox-without-downl...] as long as pdf.js is enabled. This is counter-intuitive and user-unfriendly. One shouldn't have to override settings (disable pdf.js) in about:config for an option configurable in the regular GUI to work as expected.

dandi1980 0 solutions 1 answers

Here's a link to EASILY disable the built in PDF viewer. (I tried the 'about:config' & couldn't figure it out)

How to disable the built-in PDF viewer and use another viewer|https://support.mozilla.org/en-US/kb/disable-built-pdf-viewer-and-use-another-viewer?esab=a&s=pdf&r=4&as=s

maryenc 0 solutions 1 answers

So, the problem I'm having now is that i need to provide a mailto hotlink in a PDF for others and it appears the .js version does not honor the encoded hotlinks. Any way to get around that problem since I can't control other people's Firefox options?