Compare
SRT vs TTML
SRT and TTML both time subtitles to media. SRT is a simple exchange format; TTML is XML-based and can carry richer presentation information when supported by a profile.
Which format should you choose?
Choose SRT for straightforward subtitle exchange with compatible tools. Choose TTML when the delivery workflow specifies a TTML profile or needs its supported styling and regions; verify the receiving player.
Good fit for SRT
Subtitle exchange
- Adding a separate plain-text subtitle track to a supported video player
Good fit for TTML
Broadcast and streaming captions
- Supplying styled timed captions to a system with an agreed TTML profile
Basic information
| Field | SRT | TTML |
|---|---|---|
| Extension | .srt | .ttml, .xml |
| MIME type | application/x-subrip | application/ttml+xml |
| Common uses | Subtitle exchange | Broadcast and streaming captions |
| How to open | Open in a text or subtitle editor and play it with the video to check timing. | Open and validate with a TTML-capable subtitle tool using the target profile. |
| Export or convert | When converting to WebVTT, check timestamps, line breaks, and character encoding. | When converting to WebVTT or SRT, review timing, placement, and styling that may not survive. |
Choose by use case
Adding a separate plain-text subtitle track to a supported video player
Subtitle exchange
SRTSupplying styled timed captions to a system with an agreed TTML profile
Broadcast and streaming captions
TTMLKey point 1
SRT centers on sequence numbers, times, and subtitle text.
More on the differencesKey point 2
TTML is XML-based timed text whose profiles can support styling and regions.
More on the differencesFrequently asked questions
Will SRT-to-TTML conversion preserve every subtitle feature?
Not necessarily. Check timing, line breaks, styling, and positioning in the target workflow.