How to convert SRT to VTT
- Pick the .srt caption files; several at once is fine.
- If the captions are early or late against the video, enter a shift in seconds under More settings.
- Convert and upload the .vtt files to your player or platform.
Why web players need VTT
The HTML <track> element that browsers use for captions understands WebVTT only. An SRT file looks almost identical, but it lacks the WEBVTT first line and writes milliseconds after a comma instead of a dot, and browsers refuse it for those reasons.
The converter adds the header, changes 00:00:12,400 to 00:00:12.400 and leaves out the SRT cue numbers, which WebVTT does not use. Tick Keep cue numbers if your editor prefers to see them.
Styling and placement
Italic, bold and underlined text stays as it is, since WebVTT supports the same tags. Colour tags written as <font color> are dropped because WebVTT does not support them.
Lines lifted to the top of the picture with {\an8}, often used so captions do not hide on-screen names or slides, keep that position through the line:0 cue setting. Left and right variants become align:start and align:end.
Timing and characters
The shift option moves every caption by the same number of seconds, decimals included, which fixes files made from a version of the video with a different intro. Captions that would end before the start of the video are removed.
Caption files made on older Windows PCs in Windows-1252 are detected and converted to UTF-8, the encoding WebVTT requires, so accented letters show correctly.
Questions
Are the captions uploaded?
No. Everything happens in your browser, which keeps internal training material private.
Can it stretch captions that drift over time?
No. Only a constant shift is available; drift caused by a frame-rate change needs a subtitle editor.
Can I convert a whole course at once?
Yes. Pick all the SRT files together; each gets its own VTT, and Download all packs them into one ZIP.