Text Case Converter

How Text Case Converter Works

This tool rewrites any text you type or paste into one of six case styles -- UPPERCASE, lowercase, Title Case, Sentence case, aLtErNaTiNg case, or InVERSE case -- with the conversion happening instantly as you type or switch styles.

Formula & Method

UPPERCASE and lowercase use JavaScript's built-in case conversion on the whole string. Title Case lowercases the text first, then capitalizes the first letter of every word (any word-boundary letter or digit). Sentence case lowercases the text, then capitalizes the very first letter of the text and the first letter after any ., !, or ? that's followed by whitespace -- so it treats each of those three punctuation marks as a sentence ending. aLtErNaTiNg case walks through the text letter by letter, alternating upper and lower case for each alphabetic character (starting uppercase) while leaving spaces, digits, and punctuation untouched. InVERSE case flips the case of every letter individually -- uppercase becomes lowercase and vice versa -- without lowercasing or uppercasing the rest of the text first.

Worked Example

For the input "the quick BROWN fox. hello world!", the results are: UPPERCASE → "THE QUICK BROWN FOX. HELLO WORLD!"; lowercase → "the quick brown fox. hello world!"; Title Case → "The Quick Brown Fox. Hello World!"; Sentence case → "The quick brown fox. Hello world!"; aLtErNaTiNg → "ThE qUiCk BrOwN fOx. HeLlO wOrLd!"; and InVERSE → "THE QUICK brown FOX. HELLO WORLD!" (only the already-uppercase "BROWN" flips to lowercase, since Inverse case only swaps letters that already have a case, unlike the other modes).

Frequently Asked Questions

Why did InVERSE case only change part of my text?

Inverse case swaps each letter's existing case rather than deciding case from scratch, so any letters that were already lowercase become uppercase and vice versa -- if most of your text was already lowercase, only the originally-uppercase letters will visibly change.

Does Sentence case only recognize periods as sentence endings?

No -- it capitalizes the first letter after any of three sentence-ending marks: a period, an exclamation mark, or a question mark, as long as that mark is followed by whitespace before the next letter.

Does Title Case capitalize small words like "the" or "of"?

Yes -- this converter capitalizes every word's first letter uniformly, unlike some style guides (AP, Chicago) that keep short articles and prepositions lowercase. It's a simple, consistent title case rather than a style-guide-specific one.

Can I copy the converted text with one click?

Yes -- the "Copy Result" button copies whatever is currently shown in the Converted Text box, matching the case style you have selected.