DFXP File

What are DFXP files and how to open them

Are you having problems opening a DFXP file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your DFXP files.

What is a DFXP file?

A .DFXP file is a Distribution Format Exchange Pro file.

Distribution Format Exchange Profile is a specific profile of the W3C's Timed Text Markup Language (TTML) used for subtitles and captions. It defines a set of rules and features that ensure timed text content can be exchanged among systems in a standard way, especially for distribution of captions and subtitles. It was originally developed as the TT Authoring Format (TT AF) Distribution Format Exchange Profile.

Files of this profile are created by subtitle-authoring or captioning tools when exporting timed text for media playback, streaming, or distribution. Once produced, they are read by playback systems, video platforms, editing tools, and other systems that support TTML-based timed text. These files include structured information about the caption text, timing (such as begin & end times or begin plus duration), layout (regions), and style (fonts, colors, alignment).

The Distribution Format Exchange Profile was first published by the W3C Working Group as a draft in mid-2009 and later incorporated into the finalized TTML specification in November 2010. TTML 1.0 kept the DFXP name around in its profile identifiers and allowed the extension typically used for it.

Files of this profile are written in XML, using TTML namespaces and include a root tt element containing a head section (metadata, styling, layout) and a body section (text content with timing references). They identify which DFXP profile is followed (such as presentation, transformation, or full) via a namespace or profile attribute.

Technical identifiers include starting with an ASCII < character as the first byte (beginning of XML), containing the string WWW.W3.ORG, TT XML, XMLNS, BODY, and HTTP within the data. These signatures reflect the use of XML elements and W3C namespace URIs typical of TTML-based DFXP documents.

How to open DFXP files

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

While we have not verified the app ourselves yet, our users have suggested a single DFXP opener which you will find listed below.

Last updated: October 27, 2026

Various apps that use files with this extension

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

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about DFXP file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.