Case Converter
Paste text, pick a format and get it back converted: UPPERCASE, lowercase, Title Case with every word capitalised, or Sentence case with a capital after each sentence break. Only letter casing changes — spelling, punctuation and spacing are left exactly as they were.
Sentence case is the one worth knowing about. It is the fix for text that arrived in all caps or with erratic capitalisation, because it lowercases everything and then capitalises the first letter after each full stop, question mark or exclamation mark. Retyping a paragraph to achieve that is a genuine waste of a few minutes.