Foxit Reader Provides two ways for you to open PDFs in multiple Foxit Reader Windows. Following is an introduction to these two methods.
Please go to File tab in Foxit Reader> Preferences > Documents > Open Setting > check Allow Multiple Instances, click on OK button to enable single document interface mode in Foxit Reader. This setting will enable Foxit Reader to create a new separate window when double-click to open a PDF file.
When you open some PDF files in multiple tabs in a single Foxit Reader window, please drag and drop a file tab outside of the existing window to create a new instance and view the PDF file in that individual window.
Note: This method is available in Foxit PhantomPDF 9.4 and higher versions.