Caption Cleanroom · local caption QA

Free SRT caption validator

Check an SRT file in your browser for malformed timestamps, non-positive durations, overlaps, empty captions, long lines, and a configurable reading-density heuristic. The tool does not upload or retain your text.

What it checks

• SRT timestamp syntax and cue duration
• Overlapping cue timing
• Line count and 42-character line-length guidance
• Empty captions and heuristic characters-per-second review

Open the local SRT/VTT QA tool →

It does not certify platform compliance or guarantee an upload outcome. See also SRT to VTT conversion and VTT validation.