SRT and VTT timing syntax differs
SRT uses comma milliseconds while WebVTT uses dot milliseconds and begins with a WEBVTT header. A real converter parses cues and rewrites timing deliberately.
Preserve cue text
Ordinary caption text and line breaks are kept. Unsupported style conventions are not invented.
Validate timing
End time must follow start time. Overlaps can be intentional, but malformed timestamps need review.
Test in the destination player
Players vary in how they interpret styling and line positioning. Validate the generated VTT in the actual web/video workflow.