If I have uninstalled Adobe Reader, but I can still open PDFs in Chrome, what application am I using?

I am troubleshooting a problem with opening PDFs from websites so I uninstalled Adobe Reader. Out of curiosity I checked whether I could still open PDFs from websites (here is a random example). Surprisingly I could still open PDFs from both Chrome (my preferred browser) and Internet Explorer. I believe IE is using Edge to open the PDFs but the PDF interface looks different in Chrome, so it might be another application. Unfortunately I can't uninstall Edge to check. How can I figure out what application Chrome is using to open PDFs from websites?

KAE

Posted 2018-11-27T20:25:14.860

Reputation: 1 467

21Chrome has a built-in PDF viewer, Microsoft Edge also has a built-in PDF viewer. You should be able to type "chrome://plugins" in your Chrome URL bar and see what's installed. – Andrew – 2018-11-27T20:39:33.157

I get ERR_INVALID_URL when I type chrome://plugins in my URL bar, unfortunately. – KAE – 2018-11-27T20:57:34.660

Use chrome://settings/content to control when Adobe Flash content is displayed and chrome://components to display the version of Adobe Flash Player installed.

Source: https://www.howtogeek.com/303934/what-happened-to-chrome-plugins-in-google-chrome/

– absenthecon – 2018-11-28T05:14:09.583

2all the major browsers nowadays have their built-in PDF readers – phuclv – 2018-11-28T15:32:56.427

1@Andrew, there is currently no chrome url chrome://plugins as you mentioned – KumarAnkit – 2018-11-29T07:54:33.950

I thought I'd entered some weird crossover between SU and Puzzling when I read this title. – Hashim – 2018-12-23T23:36:46.530

Answers

Chrome itself is the application that is viewing the PDFs.

Windows 10 Edge can also open PDFs directly. Please note, IE is an older, separate application from Edge. If your users start in IE, they will not be able to open PDFs directly in IE unless they have Adobe plugin installed.

Firefox is able to view PDFs without a plugin : https://support.mozilla.org/en-US/kb/view-pdf-files-firefox .

Some websites (bank websites in my experience) will force a download rather than allowing it to be opened in the same browser. In Firefox, I was able to sometimes change the behavior by changing the MIME settings, but it didn't work consistently. https://support.mozilla.org/en-US/kb/change-firefox-behavior-when-open-file

Christopher Hostage

Posted 2018-11-27T20:25:14.860

Reputation: 4 751

10"Windows 10 Edge can also open PDFs directly." Might be worth pointing out that Edge can also open EPUB files, and it does a really good job at it. – walen – 2018-11-28T08:40:41.093

4@LuisG. Edge and compliments about its performance isn't something I see very often. Is it actually good at EPUB or are you making fun of it? – Azor Ahai – 2018-11-28T19:03:25.133

1@AzorAhai, EPUB as it's actually used is basically structured HTML. I don't see why Edge would have trouble with it, if it's programed to understand the packaging. – Mark – 2018-11-28T22:20:38.740

1Note that even if the browser downloads the file because of the download headers, you can still just drag and drop the file into the browser (or use File->Open) and open the PDF file manually – SztupY – 2018-11-29T08:21:33.527

@AzorAhai I'm being serious. I've seen Edge laugh in the face of Calibre or Adobe Digital Editions after they made a mess of some weird EPUBs that Edge could show (almost) flawlessly. Example: Calibre; ADE; Edge.

– walen – 2018-11-29T09:51:44.353

From memory, Google Chrome uses a built in PDF viewer which was written in ~~JavaScript I believe~~ C++, thanks to the helpful reminder in the comments :)

This comes bundled with Chrome by default.

For me, I can view some of the related JavaScript here:

chrome-extension://mhjfbmdgcfjbbpaeojofohoefgiehjai/pdf_viewer.js

You can view some related code by opening the Chrome DevTools on the PDF Viewer.

Firefox uses another similar approach, again, written in JavaScript, although their documentation is more publicly available & from memory, is encouraged for others to use to display PDFs on their website.

Read more about Firefox's implementation here: PDF.js by Mozilla

Brandito

Posted 2018-11-27T20:25:14.860

Reputation: 201

It's written in C++, source code available here

– Paddy – 2018-11-28T08:53:04.060

As the chrome is derived from the chromium open-source project, it also uses the same embedded pdf-viewer that is shipped with Chromium Browser. So when a pdf file is encountered, chrome tries to open it using this pdf viewer.

If you open the

chrome://system

you would notice that it shows the open tabs and running extentions, but it does not shows any info about pdf viewer it is using here.

But when I open this

chrome://local-state

chrome shows multiple pdf plugin components including Adobe Reader and Chromium PDF reader. It might differ in your system.

The Readme docs are available for the chromium project, but I could not find the docs for pdf viewer. You can read it here

KumarAnkit

Posted 2018-11-27T20:25:14.860

Reputation: 173