Case converter for every kind of capital

Choose Sentence case, which restores the capital on the first word of every sentence and drops the rest. It is the right button in almost every caps-lock accident, because it restores the shape ordinary prose has rather than simply flattening the line. Pick lowercase instead when the text is a single fragment with no sentence in it — a tag, a search term, a file name — and Capitalize Each Word when the shouted line was a list of names.

Not from the converted text — that information is gone the moment the capitals fall, and no tool can tell whether an original said polish or Polish. This page works around it by never converting a conversion: every button reads the text sitting in the top box, so you can move from UPPERCASE to Sentence case to Title Case and back without the errors compounding. The safety net disappears the moment you press Put the result back in the box, which is exactly what that button is for.

No — only letters move, and everything between them stays exactly where you put it. Line breaks, blank lines, tabs, double spaces, hyphens, quotation marks and emoji all survive untouched, so a numbered list stays a numbered list and an indented block keeps its indent. Digits are unaffected too, which is why an invoice line with a product code in it comes back with the code intact.

It is the internet's tone of voice for mockery, borrowed from a 2017 SpongeBob reaction image in which a caption written in wobbling capitals reads as sarcastic repetition. Nobody uses it in serious writing, and it is included here because people arrive looking for it by name. Inverse case is its quieter cousin: every capital drops and every small letter rises, which is occasionally useful for spotting a heading whose capitals were applied in the wrong places.

Sentence case, unless a style guide you have to follow says otherwise. British newspapers moved to it decades ago and the design world has largely followed, because a heading in sentence case reads faster and stays legible when it wraps onto a second line; American newspapers and magazines, working from AP or Chicago, still set headlines in title case. The one place to avoid capitals altogether is a button or a navigation label, where an all-caps word is both slower to read and harder for people using a screen reader.

Yes for any alphabet that has two cases, so é becomes É, ñ becomes Ñ, and Greek, Cyrillic, Armenian and Coptic all convert correctly. Scripts with no capital letters at all — Chinese, Japanese, Korean, Arabic, Hebrew, Thai, Hindi and Georgian among them — pass through unchanged, which is normal rather than a failure. A German ß is the one letter that behaves oddly, because its capital is two letters rather than one.

None — there is no character cap, no daily quota and no signup. A 100,000-character chapter is recased in roughly 10 milliseconds, and a million characters in around 0.1 seconds, because every case here is a single pass over the text. The browser tab is the only real limit, and it will run out of patience with the textarea long before the conversion does.