Subtitle Validator

Drop an SRT, VTT, ASS, or SSA file here, or click to select

Validate timing, empty captions, overlapping cues, and common format structure.


            

Check subtitle files before publishing or importing them into editing software. The fixer can normalize SRT numbering, sort cues, repair small overlaps, add a WebVTT header, and validate common ASS/SSA event structure.

Subtitle files often fail because of small formatting problems: missing sequence numbers, overlapping timestamps, blank captions, wrong timestamp separators, missing WebVTT headers, or malformed ASS Dialogue lines. These issues can make platforms reject the file or show captions out of order.

Validation is useful before uploading captions to video platforms, sending subtitles to a client, importing translations into an editor, or converting between SRT and VTT.

The fixer handles common structural cleanup, but it cannot judge translation quality or whether the text matches the audio. Always preview important subtitles with the final video.

Related tools: ASS to SRT · SRT Time Shifter