Sentence Splitter: Subtitles, Translation, Proofreading
Proofreading a paragraph sentence by sentence, or turning it into subtitles, is much easier when each sentence sits on its own line.
Open the tool：Sentence Splitter
When you actually need it
Subtitles, translation review, line-by-line proofreading, and turning a long paragraph into a list all start by splitting sentences. Once each sentence is on its own line you can edit it without disturbing its neighbours and mark exactly which one needs work.
Preparing text for a speech synthesiser is another case: one sentence per line gives more natural pauses. Language-learning material benefits too, since the source and the translation can be compared line by line. A single sentence is also easy to copy for a dictionary lookup.
- Subtitle scripts and sentence-level translation
- Proofreading a long paragraph
- Read-aloud text and study material
Where it splits, and where it trips
The split happens after a period, question mark, or exclamation mark, including the full-width Chinese and Japanese forms. The punctuation stays at the end of the previous line, whitespace after it is dropped, and each sentence becomes one line, so the paragraph turns into a sequence of sentences.
Several cases break it. Abbreviations such as Dr., Mr., e.g., and U.S. split in the middle. Decimal points do too, so 3.14 becomes 3. and 14. An ellipsis can produce several fragments, and a closing quote after a period moves to the next line, so “Hi.” ends one line and the next opens with a quotation mark.
- Abbreviations like Dr. and e.g. split apart
- 3.14 becomes two sentences
- A closing quote can land on the next line
Alternatives and when not to use it
For more reliable segmentation, use an NLP library with an abbreviation dictionary, such as spaCy or NLTK's sentence tokenizer. They weigh context rather than punctuation alone, which is why they handle Dr. and U.S. correctly.
Subtitles should not be split on punctuation alone: a line that is too long cannot be read in the time it stays on screen, so length and meaning need a second pass. Chinese splits without spaces, but a closing quote or bracket at the end of a sentence can still land on the wrong line.
FAQ
Why was Dr. split from the rest of the sentence?
The tool splits after every period and does not know Dr. is an abbreviation. Join the fragments by hand afterwards, or use a sentence tokenizer that carries an abbreviation list.
What should I do with the quote that moved to the next line?
The split happens right after the period, which leaves the closing quote at the start of the next line. Move it back to the end of the previous line, or replace leading quotes in a batch and re-add them.
Does it work on Chinese sentences?
Yes. 。！？ are split points too, and Chinese needs no spaces between sentences. Closing quotes, brackets, and ellipses can still end up on the wrong line, so check the output once.
Related tool：Sentence Splitter