Invert Case swaps the case of every letter: uppercase becomes lowercase and lowercase becomes uppercase, so 'Hello World' turns into 'hELLO wORLD'. Its most practical use is recovering a paragraph typed with Caps Lock on while you were also holding Shift, which produces exactly this inverted pattern — one click restores it rather than retyping. Digits, punctuation and spacing are untouched, and accented letters are handled using proper Unicode case mapping, so é becomes É correctly. If you actually need sentence case, title case or plain lowercase, our Case Converter offers those modes instead.
Free, fast, and runs entirely in your browser — no signup, no upload to a server.