Free Caption Reading-Speed Checker
Measure each subtitle cue in words per minute and characters per second, then flag cues above practical review thresholds.
Reading-speed analysis happens in this browser. Subtitle content is not uploaded, logged, or attached to analytics events.
What this tool handles
- Input: SRT or WebVTT
- Report: TXT
- Words per minute
- Characters per second
Four checks from input to export
- 1Choose an SRT or VTT file, or paste the captions.
- 2Run the reading-speed check.
- 3Review cues flagged above 180 WPM or 20 CPS.
- 4Shorten, split, or extend those cues in the source edit.
What the browser changes
Each cue's visible characters and whitespace-delimited words are divided by its duration. The thresholds are review signals, not universal accessibility rules.
- Find short-form captions that flash too quickly.
- Review subtitle pacing before client delivery.
- Compare the effect of shorter copy or longer cue timing.
- Reading ability varies by audience, language, age, and content complexity.
- The tool does not measure font size, contrast, motion, or screen obstruction.
- Treat flags as prompts for human review, not automatic failures.
Quick answers
What reading speed is flagged?
This tool flags cues above 180 words per minute or 20 characters per second for review.
Is that an accessibility guarantee?
No. It is a practical check and cannot replace standards, user testing, or language-specific guidance.
Are tags counted?
Simple HTML-like tags are excluded from the measurement.
Need automatic transcription and animated output too? Caption Plug works in a browser or directly inside Premiere Pro.