AppHelp guide
Subtitle and Caption Timing Workflows
Learn how to convert SRT to VTT, shift subtitle timing, merge bilingual captions, and count caption text before publishing.
Quick answer
Use SRT to VTT conversion when a web player expects VTT. Shift subtitle timing when every caption is early or late by the same offset. Merge bilingual subtitles when two language tracks should appear together, and count text when caption length affects readability.
Convert format for the player
SRT is common for editing and subtitle exchange. VTT is common for web playback. Convert formats only after checking that timestamps, numbering, and cue text are valid.
Shift timing before merging
A constant offset corrects captions that are consistently early or late; it cannot fix drift that grows over time. The shifter recognizes hh:mm:ss,mmm and hh:mm:ss.mmm text, not short WebVTT mm:ss.mmm timestamps or a complete cue grammar. Negative results are clamped to zero, so review the first cues after advancing a track.
- Check the first and last caption
- Use +1500 ms to delay all timestamps by 1.5 seconds; use -1500 ms to advance them
- Keep a backup of the original subtitle file
Keep captions readable
Use character and line counts as a rough editing aid. The counter counts Unicode code points rather than displayed glyphs; a joined emoji may count as several characters. Its word rule counts ASCII word runs and individual Chinese ideographs, not general linguistic words. Check the rendered captions as well.
Frequently asked questions
Should I shift subtitles before converting SRT to VTT?
Either can work, but fixing timing before final export keeps the review flow clearer and avoids repeating conversion.
Why do bilingual subtitles feel too crowded?
Two languages can double the visible text. Count characters and shorten lines so viewers have enough time to read.