Pick a case and the text changes a moment after you stop typing, so you see what you are about to paste before you paste it. Upper and lower case use the browser’s own Unicode rules. The other five work from the A to Z alphabet, so accented and non-Latin letters come out changed in ways worth checking before you use the result.
This page loads no libraries at all. The work is done by the browser itself. Your file is read on your own machine and never sent anywhere. Open your browser’s network tab and watch while you use it.
Title case capitalises every word, including short ones like of and the, which most style guides would leave in lower case. Sentence case lowers the whole text first, then capitalises the first letter and anything that follows a full stop, question mark or exclamation mark and a space. A full stop with no space after it does not start a new sentence.
Both put the capitals back by position rather than keeping the ones you had, so acronyms, brand names and initials are flattened and iPhone becomes Iphone. Sentence case lowers everything first, so a standalone I comes back as i as well. If those need to survive, neither of the two is the right choice.
Upper and lower case do: the browser applies Unicode rules, so é becomes É and the German ß becomes SS, two letters where there was one. Title and sentence case start a word only at an A to Z letter, a digit or an underscore and step over anything else, so état comes back as éTat in title case, and sentence case leaves it in lower case.
They keep A to Z, digits and the underscore, and treat every other run of characters as the break between words. Accented and non-Latin letters are not transliterated, they go with the break: café gives caf in snake and kebab case, and café au lait gives cafAuLait in camel case.
Everything here is free and works the same way, in your browser.
A new DeskKit tool lands every week or two. Leave an address to hear about it. Nothing else is ever sent, and one click removes you.