Sentence case converter

Paste on the left and pick a Case. Sentence case lowers everything first, then capitalises the first letter after each full stop, question mark, exclamation mark and line break.

The other six are Title Case, Capitalise Each Word, UPPERCASE, lowercase, aLtErNaTiNg and iNVERSE. Swap is switched off for all of them, because lowering a capital throws away the fact that it was one.

Sentence case capitalises the first word of a sentence and nothing else. Title case capitalises most words in a heading. Mix the two across one page's headings and it looks slightly off, though few readers could say why.

Neither can be done perfectly by machine. Sentence case can't know that "paris" is a proper noun, so it won't restore the capital on a name that arrived lowercase. The one exception here is a lone "i", which is always a capital in English and is always restored.

Run the result past your own eyes. Proper nouns and acronyms are exactly what an automatic pass gets wrong, and all-caps text is the worst case, because the capitals that should have stayed were destroyed before you pasted it.

There's no single rule, and the tools disagree because the style guides disagree. AP lowercases prepositions of three letters or fewer, so it writes "Gone With the Wind". Chicago's 18th edition, from 2024, lowercases them up to four letters and writes "Gone with the Wind". MLA lowercases prepositions of any length.

The Title Case option here follows the shorter Chicago-style list, and a small word still takes a capital when it lands first in the line. For a heading that has to match a particular guide, the title case converter applies AP, Chicago, APA or MLA exactly.

Text pasted out of a PDF usually needs line breaks removed before the case is worth fixing, because a break in the middle of a sentence makes the next word look like a new sentence.

For decoration rather than correction, bubble text and upside-down text change the characters instead of their case.