This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

ابحث في الدعم

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

How does the Firefox PDF Viewer function internally?

  • 5 ردود
  • 1 has this problem
  • 2 views
  • آخر ردّ كتبه cor-el

more options

My organization has encountered a situation where some of our PDF output is not searchable when using a standard PDF viewer however, frustratingly, it is searchable when being previewed in Firefox.

I'm curious to know how the built-in PDF viewer is providing this search functionality when other document viewers are unable to do so.

This may help us solve the non-searchable PDF issue that we have.

My organization has encountered a situation where some of our PDF output is not searchable when using a standard PDF viewer however, frustratingly, it is searchable when being previewed in Firefox. I'm curious to know how the built-in PDF viewer is providing this search functionality when other document viewers are unable to do so. This may help us solve the non-searchable PDF issue that we have.

All Replies (5)

more options

You can examine some code via the resource:// URI (viewer.js):

  • view-source:resource://pdf.js/
  • view-source:resource://pdf.js/build/pdf.js
  • view-source:resource://pdf.js/web/viewer.js
more options

Are you applying security to your PDFs (e.g., no copying)? Except for the password to open the PDF, the other security settings are on the honor system, and the pdf.js viewer may disregard them.

more options

Firefox PDF Viewer isn't a complete viewer, yet. It started an an experiment - PDF.JS add-on - to create an open source PDF viewer based upon JavaScript / ECMA Script. https://en.wikipedia.org/wiki/ECMAScript

IMO it was added to Firefox as a standard feature too early - it should have remained an add-on for a longer period of time, like until it was more mature. And "as things sometimes happen" the original developer of JavaScript was forced out of Mozilla (in my opinion, that is) before PDF.JS development was anywhere near complete. And iirc that was about the time (or right after) it became a standard feature in Firefox. I have seen mention that Mozilla will be replacing that PDF.JS feature in the near future with an open-source package that has wider usage, like with another web browser. I don't recall where I read that, nor do I recall a time frame for when that may happen.

For an individual user I would recommend using a "free for personal use" PDF viewer, but for an "organization" there may be "seat license" fees involved.

more options

the-edmeister said

I have seen mention that Mozilla will be replacing that PDF.JS feature in the near future with an open-source package that has wider usage, like with another web browser. I don't recall where I read that, nor do I recall a time frame for when that may happen.

It looks like work is in process to use the PDFium library used in Chromium-based browsers, which is based on technology contributed by Foxit Software. It's not clear it will become the default, or when that might be decided.

more options