I Used to Think Longer Subtitles Were Kinder
There was a time when I put one whole sentence on each subtitle line for my short videos. I assumed it would be easier to read. Instead, the bottom of the screen filled up with text and covered the picture.
A Small Experiment
I made six short videos on the same topic and produced two versions of each.
• **Version A**: about 30 characters per line, up to two lines
• **Version B**: 16 characters or fewer per line, only one line on screen
Claude Code handled the editing. It wrote a short script that re-split the subtitle file (SRT) line by line. The video and the content stayed exactly the same, and only the way the text was divided changed.
Results
| Metric | Version A | Version B |
|---|---|---|
| Watched to the end | 31% | 44% |
| Replayed | 6% | 9% |
With only six videos, I treat this as a tendency rather than a final answer.
The Surprise
Once the lines got short, where to break them mattered more than how many characters fit. Breaking right before a particle, like 「Today's / card news」 in Korean, makes the eye snag. Breaking at a unit of meaning, like 「Today I made / a card news story」, keeps the pace natural.
One more thing: for the Chinese versions, 12 characters per line fit best. Each Chinese character carries more information, so using the Korean number made the screen feel crowded.
The Rules I Set Today
16 characters or fewer per line (Korean) / 12 or fewer (Chinese)
Break lines only at units of meaning
One line per screen
I wrote these three lines at the top of the script. From the next video on, the bot splits the subtitles by these rules first, and I only take one last look at the end.