Reading-speed warnings are review settings, not a universal pass mark
Know how this checker counts characters and why a configurable threshold cannot replace watching the video.
What the number means
The workbench divides visible character count by cue duration in seconds. It removes supported text tags for counting, decodes common text entities and ignores line-break characters. It counts spaces and Unicode code points; it does not count words, spoken syllables or grapheme clusters.
This distinction matters for mixed-language text, combined accents and emoji sequences. The result is a consistent diagnostic quantity within this tool, but it is not a psychological measurement of how fast every viewer can read.
Reproduce the arithmetic
30 counted characters / 2 seconds = 15 characters per second 30 counted characters / 1 second = 30 characters per second
A zero or negative duration cannot produce a meaningful reading speed. The checker reports that as a structural error instead of dividing by zero. Short duration, high reading speed, too many lines and long lines are independent findings; one cue can have several.
The default 20 characters per second, 42 characters per line and two lines per cue are editable review settings. They are not presented as a universal publishing requirement, a Google advertising condition or a guarantee of viewer comprehension.
Tune the review to the actual audience
Use the client's agreed style guide when one exists. For a complex educational explanation, unfamiliar terminology or a multilingual audience, inspect the exact text and context before deciding whether to shorten it, split the cue or extend its duration.
Changing a threshold to remove warnings does not change the file or make it easier to read. The report records the settings used, so two reports with different thresholds should not be compared as if they used the same standard.
Use a warning to start a review
Read the cue while watching the final video at normal speed. Check whether the sentence begins and ends naturally, whether a split produces an awkward fragment, and whether the new timing collides with another cue. The workbench will not automatically paraphrase or delete dialogue to reduce its character count.