Add your TTML file
Drop one or more .ttml 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 .ttml file to .sami 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 .ttml file to .sami extracts the document's content from its office package into a portable form. 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.
A .sami file is the same Synchronized Accessible Media Interchange caption document as .smi, written with the long form of the extension. The contents are identical — <SYNC Start=…> elements inside an HTML-like SAMI document — and the long extension is chosen mainly to avoid colliding with SMIL files, which also claim .smi. For this route the practical draw is unambiguous about which format the file actually is and identical tooling support to .smi wherever SAMI is recognised — balanced against some players recognise only .smi and must be given a renamed copy, which is worth knowing before you commit a large batch.
The practical trigger for this conversion is usually a mismatch: with .ttml, far more verbose than SubRip or WebVTT for the same cues. Switching to .sami buys you unambiguous about which format the file actually is, which is why it is the better fit for storing SAMI captions where .smi would collide with SMIL files. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
| Aspect | Timed Text Markup Language (.ttml) | SAMI captions (.sami) |
|---|---|---|
| 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 root <tt> element declares the TTML namespace and optional ttp: parameters such as frameRate, tickRate, and timeBase | byte for byte the same format as .smi: <SAMI>, <HEAD> with a <STYLE> block, and <BODY> with SYNC elements |
| Strongest at | delivering captions to broadcast and streaming platforms that mandate a TTML profile | storing SAMI captions where .smi would collide with SMIL files |
| Weak spot | far more verbose than SubRip or WebVTT for the same cues | some players recognise only .smi and must be given a renamed copy |
| Metadata | 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 | as with .smi, the style block and language classes describe presentation; only cue timing and text are carried into other formats |
Drop one or more .ttml 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 .sami in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if SAMI 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 SAMI file. Outputs keep the original filename with the .sami extension.
There is no visual quality to lose — ttml is text-oriented and sami 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 .ttml 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.
Players that read SAMI generally accept .sami as well, though a few match on .smi alone. Novus Convert treats the two identically, running the same hardened SAMI parser — no document types, no external entities, script and style content stripped — and exports any of the twelve timed-text targets.
It depends on the content: byte for byte the same format as .smi: <SAMI>, <HEAD> with a <STYLE> block, and <BODY> with SYNC elements. Convert one representative file first and compare before batch-processing a large set.
In .ttml, 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. 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 .ttml → .sami → .ttml is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.