Caption Format Reference
Caption & Subtitle File Formats
Every caption format was designed for a delivery path, and each one holds a different amount of information. These pages cover what a format can carry, who asks for it, and what changes when you convert it.
Which caption file format should I deliver?
North American broadcast expects SCC or MCC. European broadcast expects EBU-STL. Streaming platforms expect IMSC or TTML. Web players expect WebVTT, and general-purpose delivery uses SRT. Match the format to the delivery path rather than converting late in the workflow.
Format reference pages
| Format | Extension | Standard | Typically used for |
|---|---|---|---|
| SCC | .scc | EIA-608 / CEA-608 | North American broadcast and DVD authoring |
| MCC | .mcc | CEA-608 and CEA-708 | North American broadcast with 708 services |
| SRT | .srt | De facto | General-purpose subtitles and online video |
| WebVTT | .vtt | W3C WebVTT | HTML5 web players and HLS streaming |
| TTML | .ttml, .xml, .dfxp | W3C TTML | Streaming platforms and OTT delivery |
| IMSC | .ttml, .xml | W3C IMSC | Modern OTT and platform deliverables |
| EBU-STL | .stl | EBU Tech 3264 | European broadcast and teletext |
| PAC | .pac | Screen Systems Poliscript | Subtitling houses and multilingual localisation |
| Cheetah CAP | .cap | Proprietary | Legacy North American captioning workflows |
| Cavena 890 | .890 | Proprietary | Nordic and European broadcast subtitling |
| DFXP | .dfxp | TTML profile | Flash-era and platform-specific delivery |
| SAMI | .smi, .sami | Microsoft SAMI | Legacy Windows Media playback |
Closed Caption Creator reads and writes all of the above. See the complete file format support list for every format, codec and transcript type.
One project, every deliverable
Closed Caption Creator converts between 30+ caption and subtitle formats, conforms frame rates, and QC-checks the result before delivery.