Paste text, pick a case, done. Handy for headlines, essays typed in the wrong case, SHOUTING COMMENTS that need calming down, and everything between. Free, no signup.
Which case do headlines use? Title Case capitalises the main words — the style of most headlines and titles. Sentence case capitalises only the first word and proper nouns, like an ordinary sentence.
Typed a whole paragraph in caps lock? Paste it, hit Sentence case, and it's readable again — no retyping.