Open _PDF file

_PDF files: what are they and how do I open them?

_pdf file icon Are you facing difficulties opening unknown files on your computer, or wondering exactly what this file is?
We've got the information and best software solutions for opening these files effortlessly.

Renamed PDF document

Files with the _pdf extension are in most cases just standard PDF documents that had their extension renamed from PDF to _PDF. You can restore the file by changing the extension back.

Further details:

_PDF files are just renamed PDF document files, often for backup or security reasons, but still just standard PDF files.

PDF (Portable Document Format) file is a type of file format developed by Adobe Systems. It is used to present and exchange documents reliably, independent of software, hardware, or operating system.

PDF documents may can contain not only text and images, but also interactive buttons, hyperlinks, embedded fonts, video, and more. You'll often see PDF files used for forms, instruction manuals, magazine articles, and even legal documents.

Open file with:

Adobe Acrobat icon

Adobe Acrobat

A dedicated software for handling PDF documents

Adobe Acrobat for Mac icon

Adobe Acrobat for Mac

Mac version of Adobe's PDF handling software

Adobe Acrobat Reader icon

Adobe Acrobat Reader

Free reader for viewing PDF files

Adobe Acrobat Reader for Mac icon

Adobe Acrobat Reader for Mac

Mac version of Adobe's free PDF viewer

Adobe Creative Cloud icon

Adobe Creative Cloud

Latest, subscription based productivity suite from Adobe

Foxit Reader icon

Foxit Reader

A PDF viewer for Windows

iBooks for Mac icon

iBooks for Mac

Default electronic book reader included in Apple Mac OS X operating system

Okular icon


An universal document viewer for Linux

Calibre icon


A free e-book library management application

Calibre for Mac icon

Calibre for Mac

A free open source ebook creator, converter and viewer

What is the meaning of a file extension?

File extensions are characters that appear after the dot in a computer file's name. For example, the file "unknown-file._pdf" has the file extension "_pdf". This is used to identify which program should open the file or what file type it is.
File extensions help you organize and manage files. They provide a quick and easy way to identify and associate the file type with the appropriate software.

We can help you open your file

In our database, we have collected a huge number of different file extensions, detailed descriptions, and programs that can be used to open or otherwise work with the file extensions listed in our database.
This database is an invaluable resource for users who want to understand better file extensions and what they can do with them. It also allows users to know different file types with the same purpose.

Only verified software links are provided

We have verified every software listed in our database. The software listed in our database includes links to the developer's or software's website. These links should allow you to download the right program for each file type. Using verified software from reputable sources helps minimize the risk of malware and viruses infecting your computer.