Sentence Case Converter
Intelligently capitalise the first letter of each sentence. Handles multiple sentences, preserves proper nouns option, and supports all punctuation terminators.
Frequently Asked Questions
What does sentence case mean?
Sentence case means only the first letter of each sentence is capitalised, with all other letters in lowercase — exactly as you would write a normal sentence. For example, "THE QUICK BROWN FOX. IT JUMPS HIGH." becomes "The quick brown fox. It jumps high." This differs from Title Case (every word capitalised) or ALL CAPS.
How are sentence boundaries detected?
The tool splits on full stops, exclamation marks, and question marks followed by whitespace or end-of-string. It also handles ellipses (…) and multiple punctuation marks (e.g. "?!"). Each detected sentence start is then capitalised.
What does "Preserve all-caps words" do?
When enabled, words that are entirely uppercase (like "NASA", "HTML", "CEO") are left untouched, because they are likely acronyms or abbreviations. When disabled, those words are also lowercased and only the sentence-start letter is capitalised.