_PDF File Type

- The quick facts

What are _PDF files and how to open them

Are you having problems opening a _PDF file or just wondering what they contain? We explain what these files are used for and show you software that we know can open or otherwise handle your files.

What is a _PDF file?

These _PDF files are generated by Microsoft Live Mail. This software sometimes changes the extension of PDF files from the standard .pdf extension to _pdf.This usually happens when the PDF file has a dot (.) at the end of the file name and another dot for the extension. Because a dot should separate the file name from the extension, some programs like Windows Live Mail may change the dot of the extension to an underscore in instances where there are two dots before the extension.Other users claim that Microsoft Live Mail and newer versions of Internet Explorer may sometimes do this upon transmitting PDF documents to and from the Internet, even if there is only one dot before the extension. To open _PDF files, simply rename the PDF document to a standard .pdf file. This means you must delete the underscore () and ensure that there is only one dot before the PDF extension.

How to open _PDF files

Important: Different programs may use files with the _PDF file extension for different purposes, so unless you are sure which format your _PDF file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested 6 different _PDF openers which you will find listed below.

Last updated: December 15, 2021

Suggest another file format using extension _PDF

While we know of one file format using the ._PDF file extension, there may be more. It is widespread that different programs use files with the same file extension for very different types of data. Please let us know if you are aware of a different kind of ._PDF file.

Various apps that use files with this extension

These apps are known to open certain types of _PDF files. Remember, different programs may use _PDF files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Adobe AcrobatAdobe AcrobatUser submitted
Adobe PhotoshopAdobe PhotoshopUser submitted
Microsoft OfficeMicrosoft OfficeUser submitted
PDF Complete Special EditionPDF Complete Special EditionUser submitted
Foxit J-ReaderFoxit J-ReaderUser submitted
Nitro ReaderNitro ReaderUser submitted
We have not verified any software that we know for certain will work with _PDF-files on Mac. If you know one, please use the 'Suggest a program' link below and tell us about it!
We have not verified any web services that we know for certain will work with _PDF-files. If you know one, please use the 'Suggest a program' link below and tell us about it!