What Is the File Extension API?

While computer files are typically thought of as containing data that can be retrieved and read as text, there are some file extensions that are associated with executable programs. The API file extension is used for files which add functionality and features to other programs.

Full Extension Name

The API file extension is an abbreviation of the full extension name, Acrobat Plug-In.

Associated Program

A file with an API file extension is typically associated with Adobe Acrobat or Adobe Acrobat Reader, programs created by Adobe Systems. These programs are most commonly known as those used to open and create PDFs (Portable Document Files).

File Format

API files are not designed to be used as an independent file format. A plug-in file adds optional functionality to an existing program. They are sometimes referred to as "add-ons" or "helper applications."

Corresponding File Formats

An API does not open in conjunction with another file format as it doesn't hold changeable data. Instead, the file is executable, meaning it can be opened and installed alongside another program, giving the program extra features.

Compatible Programs

Files with the API extension are most commonly used in conjunction with Adobe's Acrobat software. However, they can also be used with the printer functions of IBM Lotus Software and Adobe Photoshop as well as with Apple's Web application framework, WebObjects Interface.