Answer
Since they’re different products, Foxit PDF Reader and Foxit PDF Editor can run at the same time. And you can have different PDFs open in each program at the same time. But that’s not the easiest way to compare versions of the same PDF file against each other.
If you need to read two PDF documents side by side to compare contents, make changes, and even copy content from one to the other, Foxit PDF Reader and Foxit PDF Editor both give you easy ways to do it. And they don’t require you to have both programs open simultaneously.
Instead, you can allow multiple instances/windows of Foxit PDF Reader or Foxit PDF Editor to be open simultaneously,use the Split View feature, or use the New Horizontal/Vertical Tab Group feature.
Allow multiple instances/Always open files in a new window
To enable the “allow multiple instances” or "Always open files in a new window" feature, go to File > Preferences > Documents > and check “Allow multiple instances” or “Always open files in a new window". Now whenever you double-click a new PDF file, Foxit PDF Reader or Foxit PDF Editor will open a separate window.
If you need to do this on the fly, just drag and drop the document’s tab outside of its current window and a new window will be displayed.
Note: The option “Open in multiple instances” has been updated to “Always open files in a new window" since version 13.0 and Version 2023.2.
Split View
If you want a side by side—or top and bottom—comparison of different pages within the same document, you can use Foxit PDF Reader’s split view feature to view different instances of a document within the same tab. To do this, simply click View > Split, then choose whether you want to split your view vertically or horizontally.
With this feature, you can scroll, zoom, or turn to other pages in one pane without having it affecting the other.
New Horizontal/Vertical Tab Group
This feature allows you to view two or more PDF files side-by-side (either horizontally or vertically) in the same window, instead of creating multiple instances/windows. For details about how it works,please refer to this article.
Is there a way to do compare PDF documents and get reports on differences?
Yes! To compare two versions of the same PDF document, go to View > Compare to view both documents side by side. The result is very similar to the way you do compare documents in Microsoft Word and view the resulting differences.
With Foxit PDF Editor, all it takes is a few clicks to view two or more files at once without having to switch back-and-forth between tabs.
For more details, check out our tutorial video here.