Add your DFXP file
Drop one or more .dfxp files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Converting a .dfxp file to .ttml extracts the document's content from its office package into a portable form. Free, private, and validated — the file never leaves your browser.
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.Converting a .dfxp file to .ttml extracts the document's content from its office package into a portable form. 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.
A .ttml file is a Timed Text Markup Language document: an XML vocabulary in which each <p> element carries begin and end (or dur) attributes plus the caption text. It is the W3C standard that broadcast and streaming systems use as their interchange format for captions and subtitles. For this route the practical draw is a real published standard with formal profiles rather than a de facto convention and expresses styling, layout, and regions that plain caption formats cannot — balanced against far more verbose than SubRip or WebVTT for the same cues, which is worth knowing before you commit a large batch.
The practical trigger for this conversion is usually a mismatch: with .dfxp, the distinct extension implies a distinct format and regularly confuses tooling. Switching to .ttml buys you a real published standard with formal profiles rather than a de facto convention, which is why it is the better fit for delivering captions to broadcast and streaming platforms that mandate a TTML profile. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
| Aspect | DFXP timed text (.dfxp) | Timed Text Markup Language (.ttml) |
|---|---|---|
| Format type | Text-based — characters and structure, so there is no visual quality loss | Text-based — characters and structure, so there is no visual quality loss |
| How it stores data | the document is TTML: a <tt> root, a <body>/<div> structure, and <p> cues with begin and end attributes | the root <tt> element declares the TTML namespace and optional ttp: parameters such as frameRate, tickRate, and timeBase |
| Strongest at | delivering captions to a platform whose spec names DFXP by extension | delivering captions to broadcast and streaming platforms that mandate a TTML profile |
| Weak spot | the distinct extension implies a distinct format and regularly confuses tooling | far more verbose than SubRip or WebVTT for the same cues |
| Metadata | profile and parameter attributes are read for timing purposes only; styling and layout are not carried into caption targets that cannot express them | styling, layout, and region definitions are read past rather than applied: timing and text convert, presentation does not, and no external resource is ever fetched |
Drop one or more .dfxp files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Select .ttml in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if TTML is selectable, the route is real and validated.
Press Convert. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded.
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid TTML file. Outputs keep the original filename with the .ttml extension.
There is no visual quality to lose — dfxp is text-oriented and ttml is text-oriented, so the question is structural fidelity. Text, ordering, and basic structure are preserved; complex layout, embedded objects, and styling beyond the target's model are simplified.
Yes — the .dfxp file is processed inside your browser tab and never uploaded. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded. Close the tab and the file is gone from memory.
Broadcast and streaming toolchains — including the DFXP, SMPTE-TT, EBU-TT, and IMSC profiles — read and write TTML, and caption editors such as Subtitle Edit export it. Browsers do not. Novus Convert parses TTML locally with document types and external entities refused outright, resolves all five time-expression shapes, and converts to any of the twelve timed-text targets.
It depends on the content: the root <tt> element declares the TTML namespace and optional ttp: parameters such as frameRate, tickRate, and timeBase. Convert one representative file first and compare before batch-processing a large set.
In .dfxp, profile and parameter attributes are read for timing purposes only; styling and layout are not carried into caption targets that cannot express them. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .dfxp → .ttml → .dfxp is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.