PDF File Extension

Portable Document Format

File Type pdf
Developer Adobe Systems
Popularity
4.2 (37 votes)
Application Adobe Acrobat Reader DC
Category Document Files, eBook Files
Format Binary

What is a PDF file?

Portable Document Format files, recognized by the PDF extension, fall into the Document Files and eBook Files categories, amounting to 1043 files.

The Portable Document Format (PDF) was created by Adobe, a company that developed file format and produced 81 programs for their use.

PDF files are compatible with various operating systems, including Windows, Mac OS and Linux as well as mobile platforms such as Apple iOS. If you need to open a PDF file, you can use one of 42 programs, such as Adobe Acrobat Reader DC, Nitro Pro and Adobe Illustrator.

MIME types

application/x-pdf
application/x-bzpdf
text/x-pdf
application/acrobat
applications/vnd.pdf
application/pdf
application/x-gzpdf
text/pdf

File Signature

HEX code: 25 50 44 46 2D 31 2E. ASCII code: %PDF-1..

How to open a PDF file?

If you’re having difficulty opening a PDF file, it is often due to not having the correct software. To solve the problem, choose a compatible program from the list. Then follow the link to the official developer site, download the software, and install it on your device.

Adobe Acrobat Reader DC, Nitro Pro and Adobe Illustrator are recognized as the most popular software solutions for dealing with PDF files. To install the most up-to-date edition of Adobe Acrobat Reader DC, visit the official Adobe website. You can download the build that works across all operating systems.

Once the process is complete, Adobe Acrobat Reader DC should take over as the default application for PDF files.

Set Adobe Acrobat Reader DC as the default PDF handler

Setting a default program by file type in Windows

Right-click your PDF file, then navigate to the "Open With" option and click "Choose Another Application" to continue;
In the pop-up window, find and select the Adobe Acrobat Reader DC application from the available options;
Make sure the "Always use this app" checkbox is checked and click "OK" to confirm your choice as the default app for opening PDF files.

Choose an app to open a file on Mac

Right click or use Control + left click on the desired PDF file to launch the file options menu;
Select "Open in application" and click "Other";
At the bottom of the window, you will find the "Enable" menu. Default, will be set to "Recommended Programs";
Choose "All Programs" in this menu and search for Adobe Acrobat Reader DC. Check the box next to "Always open in app" to make it the default program.

How to edit a PDF file?

Editing PDF files requires installing professional software that lets you open and edit document files. Online editors have more limitations compared to dedicated Portable Document Format programs.

List of Top PDF editors 2026

Based on the criteria above, here is a selection of PDF editors you can use.

PDF Editor Software	Developer	Platforms	Overall Rating
Compress PDF	Gerald Ni	Mac OS	4.5 out of 5 (37 reviews)
Adobe Acrobat Pro DC	Adobe	Windows, Mac OS	4.4 out of 5 (35 reviews)
Nitro Pro	Nitro	Windows	4.4 out of 5 (36 reviews)
PDF Architect	pdfforge	Windows	4.3 out of 5 (39 reviews)
Adobe Illustrator	Adobe	Windows, Mac OS	4.2 out of 5 (39 reviews)
Affinity Photo	Serif Europe	Windows, Mac OS	4.1 out of 5 (41 review)

Convert to and from PDF

When a PDF file is not easy to work with, converting it to formats like DXF, DWG, JPG, JPEG, GIF or other comparable types may help.

Converting a PDF file may not fully retain all functionality, but it is generally possible to return it to the original format.

Offline software, including Adobe Acrobat Pro DC, PDF Architect and Calibre, allows smooth conversion of PDF files while preserving original quality.

Convert PDF to other file formats

Converting Files to PDF Format

Effective solutions for PDF file problems

Rest assured, any issues with PDF files can typically be addressed with simple software adjustments. See the tips below for help.

Are there any techniques or tools available to repair a damaged PDF file?

Open the damaged PDF file using Advanced PDF Repair, and then select the "Repair" menu item to start the repair process. Allow the recovery process to complete, which will automatically repair the damaged document files.

What are the telltale signs of a corrupt PDF file?

Corrupted PDF document files may show the following signs:

Unexpected expansion of the total size of the PDF file;
Opening the file in Adobe Acrobat Reader DC or other programs causes them to hang or crash;
Opening the file results in an error or a failed attempt;
While working with the file, error messages appear;
Editing the archive in Adobe Acrobat Pro DC is accompanied by slow performance or delays;

What factors contribute to Adobe Acrobat Reader DC crash?

Adobe Acrobat Reader DC crashes can occur due to outdated software versions. To mitigate this, install the latest updates for Adobe products.

Restarting your computer can resolve numerous common problems, so it should be the initial step before changing any software-related settings.