This article describes what an XFDL file is, how to open it, and how to save it as PDF or another format such as HTML.

A file with the XFDL file extension is an Extensible Forms Description Language file. It is a secure XML file type developed by PureEdge Solutions (a company acquired by IBM in 2005) as a way to create secure and legal electronic forms.

These files are most commonly used in a business or government context when transferring data or buying and selling things over the Internet. The data in a file typically consists of things like transaction details and digital signatures.

The format supports multiple digital signatures, with each signature being applied to different sections of the form to prevent content changes. The U.S. military once used XFDL for their forms, but later migrated to fillable PDFs.