SRT vs WebVTT: which subtitle format do you need?
Use the subtitle format required by your destination player or editor. SRT is a simple numbered-cue format; WebVTT adds a header and supports structures such as cue settings, regions and styles. Converting the file structure is different from changing its extension.
Start with the destination
Check which subtitle format your publishing workflow accepts before converting. A supported extension alone does not guarantee that every styling feature will render. Test a few cues in the destination, including one with formatting and one near the end.
The W3C WebVTT specification defines timed text and additional layout features. CueRefine deliberately supports a bounded subset for editing and conversion; a valid WebVTT file can still contain structures this tool will not convert.
Read the timing line
An SRT cue normally has a sequence number, a time range such as 00:00:01,200 --> 00:00:04,400, and text. A WebVTT document starts with WEBVTT and uses a dot in the millisecond part. CueRefine converts that syntax without changing the numeric times.
A conversion checklist
Keep the original. Open the file and inspect all diagnostics. Read each listed format loss. Only acknowledge it if the destination does not need that information. Download the new file, then check dialogue and formatting in its actual player.
For example, a VTT position setting is presentation data, not spoken dialogue. Removing it can preserve the words while changing where those words appear. That is why CueRefine asks you to review losses rather than describing all conversion as lossless.
When to keep WebVTT
Keep VTT if your workflow depends on its styles, regions, identifiers or cue settings. CueRefine preserves untouched same-format source bytes and keeps supported surrounding blocks when editing. Cross-format conversion cannot promise that same fidelity.
Inline cue timestamps and streaming time mappings require additional timing semantics. CueRefine blocks their conversion and shifting rather than trying to infer the intended playback behavior.
| Feature | SRT → VTT in CueRefine | VTT → SRT in CueRefine |
|---|---|---|
| Cue text and start/end times | Preserved, subject to markup review | Preserved, subject to markup review |
| Bold / italic / underline tags | Kept | Kept |
| Cue numbering / identifiers | Numeric SRT identifiers omitted | New sequential SRT numbers; VTT identifiers reported as losses |
| Styles, regions and positioning | Not created | Reported for loss acknowledgement |
| Inline timestamps / stream mappings | Unsupported structures block conversion | Unsupported structures block conversion |
References
Examples and product behavior checked on October 9, 2026.