Caption Check

Choose an SRT or WebVTT file to find broken timestamps, empty cues and sequence-number problems. Reading speed, line length, duration and overlaps appear separately as warnings for you to review.

Each finding includes its source line and cue text. Save an HTML report or JSON findings; your original subtitle files stay unchanged. The example is synthetic, so you can try the controls before choosing a file.

The checker processes files locally in your browser: up to 10 UTF-8 files, 2 MiB each. It does not check audio alignment, translation or acceptance by a particular platform.

An optional £5 offline edition packages the same checks in one HTML file with a guide and MIT source. The link is below the checker. There is no subscription.

If a finding is confusing, leave a comment with the smallest non-sensitive example that shows it. Keep private subtitle files out of public comments.