Case Converter
Paste text, pick a case — the result updates live and never leaves your browser.
Seven cases, one honest rulebook
UPPERCASE and lowercase are simple, but the other modes hide real rules. Our Title Case capitalizes every word except short function words — a, an, and, as, at, but, by, for, in, nor, of, on, or, so, the, to, up, yet — unless one of them is the first or last word, which always gets a capital. Sentence case lowercases everything, then capitalizes the first letter after each sentence boundary (., !, ?) and fixes any standalone "i" back to "I". The developer cases split your text on anything that isn't a letter or number (Unicode-aware, so accented words survive), lowercase the pieces, then join them: camelCase capitalizes each word after the first, snake_case joins with underscores, and kebab-case joins with hyphens.
Worked example
Input: the art of naming things in code
- UPPERCASE →
THE ART OF NAMING THINGS IN CODE - lowercase →
the art of naming things in code - Title Case →
The Art of Naming Things in Code - Sentence case →
The art of naming things in code - camelCase →
theArtOfNamingThingsInCode - snake_case →
the_art_of_naming_things_in_code - kebab-case →
the-art-of-naming-things-in-code
Note how Title Case keeps "of" and "in" lowercase mid-title but still capitalizes "The" as the first word.
Frequently asked questions
Which words stay lowercase in Title Case?
This converter keeps short function words lowercase unless they're the first or last word: a, an, and, as, at, but, by, for, in, nor, of, on, or, so, the, to, up, yet. Be aware that style guides genuinely differ — AP style lowercases short prepositions but capitalizes any word of four letters or more, while Chicago lowercases prepositions regardless of length. If you write for a specific publication, check its guide.
What's the difference between camelCase and PascalCase?
Both remove separators and capitalize word starts; the only difference is the first letter. camelCase starts lowercase (userName), PascalCase starts uppercase (UserName). This tool produces camelCase — for PascalCase, just capitalize the first letter of the result.
When should I use snake_case vs kebab-case?
snake_case (words_joined_with_underscores) is the convention in code: Python variables, database columns, many config keys. kebab-case (words-joined-with-hyphens) belongs in URLs and file names for the web, because search engines treat hyphens as word separators and underscores can't appear in domain names or CSS-friendly identifiers.
Does it handle accented letters like é or ü?
Yes. The word-splitting uses a Unicode-aware pattern (letters and numbers in any script), so café becomes café in camelCase output rather than being split or dropped, and uppercase/lowercase conversion follows Unicode rules — É lowercases to é correctly.