About the Sentence Case Converter
Sentence case is the standard capitalization style of ordinary prose: one capital letter at the start of each sentence, the pronoun "I" capitalized wherever it appears, and everything else lowercase (aside from proper nouns, which this automated conversion cannot detect). This tool applies that convention the same way the "Sentence case" option in a word processor does — it lowercases the entire block of text, then walks through it capitalizing the first letter after the start of the text and after every period, question mark, or exclamation point.
The conversion steps
- Lowercase everything. Every letter in the input is converted to lowercase first, regardless of its original case — this is what separates sentence case from title case or a simple capitalize-first-letter pass.
- Capitalize sentence starts. The first letter of the text is capitalized, and so is the first letter following any ".", "!", or "?" — the standard three sentence-ending marks.
- Capitalize standalone "I". English always capitalizes the pronoun "I" on its own (and in contractions like "I'm" or "I'll"), even in the middle of a sentence, so this is applied as a separate pass when the option is enabled.
- Optional line-break rule. When "Treat new lines as sentence breaks" is on, each new line also gets a capital letter, which helps with lists, addresses, or text that was line-wrapped without ending punctuation.
What the results mean
Alongside the converted text, the tool reports how many sentences it found (by splitting on runs of "." "!" and "?"), the word and character counts of your input, and how many individual characters had their case changed — a quick way to see how much of the original formatting was touched.