Caption readability report
1 of 2 cues need review Cue 2: 12.9 chars/sec · 45 max line characters
Thresholds: 20 chars/sec and 42 characters per line.
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Formula or method
Characters per second = visible cue characters ÷ cue durationAssumptions
- Reading comfort varies by audience, language, and content complexity.
- The checker flags likely review points rather than declaring captions compliant.
Sources and verification
- Described and Captioned Media Program: Captioning standards and presentation-rate guidanceProvides established caption duration and reading-rate guidance used as context for subtitle checks.
How to use the reading speed
Flag cues that exceed the selected characters-per-second or line-length thresholds. The report identifies likely review points, not automatic failures; comfortable reading depends on language, age, vocabulary, sound, shot changes, and the information shown on screen.
Review a flagged cue in context
A one-second cue containing forty visible characters reaches forty characters per second and will be flagged under a twenty-character threshold. First confirm that the timestamp is correct, then consider extending the cue, splitting it at a natural boundary, or shortening wording without changing meaning.
Line-length flags identify dense lines but cannot see font, player width, speaker labels, or safe areas. Review actual line breaks in the target player and keep related words together rather than breaking only to satisfy a character count.
Use thresholds as a consistent review profile
Choose a documented profile for the audience and delivery context, then apply it consistently across the program. Educational, children's, multilingual, and technically dense content may need more reading time than casual dialogue.
Subtitle text is processed locally. The checker removes basic markup when measuring visible characters, but complex styling, ruby text, positioned cues, and non-Latin writing systems may need specialized tools and human accessibility review.
Questions about this tool
What characters-per-second limit should I choose?
Use the standard required by the broadcaster, platform, client, or accessibility program. When none applies, choose a documented profile and test it with the intended audience.
Will the checker rewrite fast captions?
No. It reports likely issues so a person can adjust timing or wording while preserving meaning, speaker intent, and synchronization.
Are subtitle files sent to a server?
No. The current checker parses and measures the supplied subtitle text in the browser.