Paste text, pick a case, and copy. Everything runs in your browser.
Changing the case of text, to UPPERCASE, lowercase, Title Case or Sentence case, is a small job that comes up constantly when cleaning up headings, data or copied text. The tool above converts between them instantly, which beats retyping or fiddling in a word processor, especially for a block of text that arrived in the wrong case.
The conventions. Sentence case capitalises only the first word and proper nouns, and is increasingly preferred for headings because it reads more naturally. Title Case capitalises the main words and is the traditional style for titles, though the exact rules (which small words to leave lowercase) vary between style guides. UPPERCASE shouts and reduces readability in long stretches, so it is best kept for short labels.
Cleaning up data. Case tools are handy for normalising messy input, for example making a list of names or emails consistent, or fixing text that came in ALL CAPS from a form. When consistency matters more than style, pick one case and apply it across the whole field so downstream sorting and matching behave predictably.