Subtitle Line Breaker

How many characters per line should a subtitle have?

A subtitle is read in a second or two, so the place where a line ends matters almost as much as the words. Most style guides allow two lines and cap the characters per line: 42 for Netflix and TED, 37 for the BBC and the German-language broadcasters, about 32 for vertical video on a phone. Longer lines can be cut off at the edge of the picture or shrink until they are hard to read.

A good break follows the grammar of the sentence. This subtitle line breaker prefers to break after punctuation and before conjunctions and prepositions, and it never ends a line on an article, so “the” stays with its noun. Dialogue lines that start with a dash keep a line of their own. Separate rule sets for English, German, French and Spanish decide which small words are treated as articles, conjunctions and prepositions.

The shape of the lines is a matter of house style. Balanced makes both lines about the same length, pyramid keeps the top line shorter so that less of the picture is covered, and top-heavy puts more text first. When a subtitle needs more lines than allowed, the tool can split it into two subtitles and share the display time by text length. Anything still over the limit is marked in red.

Line length limits of common subtitle standards

Tips

• Not sure whether a file needs work? Measure it first with the Subtitle Character Counter: it shows the longest line and how many subtitles are over the limit.
• Splitting a long subtitle in two gives each half less time on screen. If some of them end up too short, the Subtitle Duration Fixer extends them where the next subtitle leaves room.
• Shorter lines do not make a subtitle quicker to read. Check the reading speed with the Subtitle CPS Calculator and trim the wording where it is above the limit.
• Set the few breaks you want to decide yourself in the SRT Editor, then confirm the whole file with the SRT Validator.