Subtitle Editor & Converter
Validate SRT or WebVTT captions, correct timing scale and offset, review readability and download captions plus a review report.
1. Edit your captions
2. Adjust & convert
Positive values make captions appear later. Negative values make them appear earlier.
Advanced timing & review
100% keeps original timing. 110% multiplies timestamps by 1.1, then applies the shift. Text is unchanged.
Review flags: two lines, 42 Unicode code points per line, 20 per second and 500 ms minimum. These are advisory; language and audience needs vary. Markup counts as text.
Edit existing captions here. This tool does not generate captions from audio.
3. Review & save
Your result will appear here. Start with the example or paste your own text.
Practical example
Shift a cue from 00:00:01,000–00:00:03,000 by 500 ms to 00:00:01,500–00:00:03,500.
Limits · supported files
Plain SRT and WebVTT cue text only, up to 200,000 characters and 2,000 cues, timestamps within seven days. Style, region, positioning, named cue identifiers and NOTE blocks are unsupported and rejected. Timing scale is 50–200% before the millisecond offset. Advisory review flags cover overlaps, line lengths, reading rate and short cues; they do not certify accessibility or transcription accuracy. Caption generation from audio is not supported. Review timings against your recording.
Step-by-step guide
How to use Subtitle Editor & ConverterReview the example, result checks and limitations before using your own inputs.