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Document format

DFXP converter

A .dfxp file is a TTML document written to the Distribution Format Exchange Profile — the profile the W3C defined for handing finished captions to a distributor. The extension signals the profile; the contents are ordinary TTML, which is why the same parser reads both.

Private for supported formats — processed in your browser

Convert supported files

Runs on your device

Drop DFXP files here

Batch files can each use a different output. Nothing uploads for local conversions.

Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.

Where DFXP comes from

DFXP was the working name of TTML 1.0 during its development at the W3C, and the .dfxp extension stuck as the practical filename for the presentation profile. Adobe's Flash captioning and later Netflix, Amazon, and Brightcove delivery specifications all standardised on it, which is why it remains common in media supply chains long after the format itself was renamed TTML.

How DFXP works

  • The document is TTML: a <tt> root, a <body>/<div> structure, and <p> cues with begin and end attributes.
  • The presentation profile is declared with ttp:profile pointing at the W3C dfxp-presentation profile URI.
  • Time expressions are usually clock times with a media time base, which keeps cue timing independent of frame rate.
  • Because DFXP is a profile rather than a separate grammar, a .dfxp file renamed to .ttml is still valid.

When to use DFXP

  • Delivering captions to a platform whose spec names DFXP by extension
  • Moving captions through media supply chains built around Adobe-era tooling
  • Converting a distributor's DFXP deliverable into WebVTT for a website
  • Round-tripping captions between TTML-based systems without losing timing

Strengths and limitations

Strengths

  • Accepted by name across a wide set of streaming ingest specifications
  • Fully TTML, so any TTML tool can read and validate it
  • Millisecond clock timing avoids frame-rate ambiguity

Limitations

  • The distinct extension implies a distinct format and regularly confuses tooling
  • As verbose as any TTML document for what is often plain dialogue
  • Not playable in a browser without conversion

Compatibility

Streaming ingest pipelines, caption editors such as Subtitle Edit and CaptionMaker, and any TTML-aware library open .dfxp. Browsers and consumer players do not. Novus Convert reads it through the same hardened TTML parser used for .ttml — no document types, no external entities, no network access — and writes any of the twelve timed-text targets.

Profile and parameter attributes are read for timing purposes only; styling and layout are not carried into caption targets that cannot express them.

Convert DFXP to another format

Convert other formats to DFXP