Even better, Firefox’s PDF viewer comes enabled by default. That means when you click on a PDF file link or open it from the Downloads panel, it will be opened by the built-in PDF viewer.
Here, we’ll take a look at how to open PDFs using Firefox’s built-in viewer.
How to Enable Firefox’s Built-In Viewer to Open PDF Files
In case that you’ve turned off the PDF or it’s not enabled, you can always go switch it on by following these steps:
Go to Menu > Downloads or press CTRL+J to open your downloads. Right-click on a PDF file from the Downloads list. Select Always Open in System Viewer from the drop-down menu. Once that’s selected, all your PDF files will be opened by the in-built viewer whenever you click on one.
That’s not all! Firefox’s built-in PDF viewer does a lot more than just opening and viewing PDF files.
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How to Fill Out Forms in Firefox’s PDF Viewer
Starting with the version 93.0 update, Firefox’s PDF viewer allowed users to fill out XFA-based forms, used by governments, banks, and organizations. Here’s how to fill out forms in the PDF viewer:
Open a PDF file that has interactive fields. Fill out such check boxes, radio buttons, and text fields with relevant information. Once you’re entering your data, download the PDF so that the filled-out version is saved to your computer.
How to Disable Firefox’s Built-In PDF Viewer
If you’d like to use another PDF viewer or just don’t like Firefox’s one, you must first disable Firefox’s built-in PDF viewer.
Click on the Menu button, and select Settings. Go down to the Applications section in the General panel. Find PDF and click on it. Click on the arrow under the Action column and select your new PDF viewer from the drop-down menu.
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How to Opt for a Third-Party PDF Viewer
You can use another third-party PDF viewer to open a PDF file, even when the default viewer is set to Firefox’s built-in PDF viewer. Here’s how.
Go to Menu and open the Downloads panel. Right-click on the folder icon of the PDF file you’d want to open. Choose Open Containing Folder from the drop-down menu. When you’re in the Downloads folder, right-click on the file. Select Open with and choose the PDF viewer you’d prefer.
Opening PDFs with Firefox is Easy
Firefox’s built-in PDF viewer allows you to view PDF files in the browser window, effortlessly. It also has useful toolbar functions that help you navigate a file better.
You can enter the page number to skip pages, change the size of the document, or view it in presentation mode by clicking on the full-screen button.
