Merge Lines with Same Text
Merge consecutive subtitle lines that have identical text content into one entry covering the combined time span.
- Menu: Tools → Merge lines with same text…

Options
- Max ms between lines — Only merge lines that are at most this many milliseconds apart
- Include incrementing lines — Also merge sequences where the text increments (e.g. countdowns or revealing text)
The preview updates live; uncheck any group in the list to exclude it before clicking OK.