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YouTube Caption Readability Analyzer

Review caption line length, line count, characters per second, cue duration and adjacent overlaps using configurable thresholds.

Free browser toolRuns in your browserNo sign-up

Technical review

3 of 3 cues need review

Thresholds are configurable review prompts. Language, speaker labels, sound descriptions and synchronization still require human review.

Parsed cues

3

Flagged cues

3

Reflow state

Original text

00:00:00,000 → 00:00:03,200

1 issue

Clear captions help viewers follow the explanation.

14.1 characters/second

  • • Longest line is 51 characters.

00:00:03,400 → 00:00:07,100

1 issue

Review timing, line length and the words on screen.

11.6 characters/second

  • • Longest line is 51 characters.

00:00:07,300 → 00:00:10,800

1 issue

Then upload the finished caption file with the video.

12.9 characters/second

  • • Longest line is 53 characters.

About the YouTube Caption Readability Analyzer

YouTube Caption Readability Analyzer parses an SRT or WebVTT file and reviews each cue against adjustable maximum line length, line count, characters-per-second and minimum-duration thresholds. Adjacent overlaps are reported alongside those checks.

Every cue displays its timing, text, calculated reading speed and specific review messages. The reflow action wraps text at the selected character limit without changing words or timestamps, and the reviewed file can be downloaded.

Thresholds are technical prompts rather than universal accessibility decisions. Human review is still required for synchronization, punctuation, speaker labels, meaningful sound descriptions, language accuracy and reading flow.

Key features

  • SRT and WebVTT parsing
  • Maximum characters-per-line check
  • Maximum lines-per-cue check
  • Characters-per-second calculation
  • Minimum cue-duration check
  • Adjacent-overlap warning
  • Local line reflow
  • Reviewed caption download

How to use

  1. 1Paste the final SRT or WebVTT draft.
  2. 2Set the technical thresholds appropriate for the language and publishing context.
  3. 3Review every flagged cue and inspect the calculated reading speed.
  4. 4Optionally reflow long lines, then complete human synchronization and accessibility review.

Examples

Review a tutorial caption file
Input: SRT file, 42 characters per line, two lines, 20 characters per second and one-second minimum
Output: Cue-level warnings plus an optional reflowed SRT

Complete human review for synchronization, names, speaker context and sound descriptions.

Frequently asked questions

Does a passed cue guarantee accessibility?
No. The checks cover a limited set of measurable properties and cannot judge language, synchronization or meaningful sound descriptions.
What does characters per second measure?
It divides non-space caption characters by the cue's on-screen duration as a reading-speed signal.
Does reflow change timestamps?
No. It wraps text at the selected line length while preserving cue start and end times.
Can I change the thresholds?
Yes. Line length, line count, reading speed and minimum duration are all adjustable.

Continue your workflow

Open a related tool to prepare your files or refine the finished result.