Case Converter

Retyping text because the capitalisation is wrong is tedious. This case converter changes your text between UPPERCASE, lowercase, Title Case, Sentence case and the naming styles programmers use: camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE. Paste your text, press a button, copy the result.

It works in your browser, supports accented letters, and keeps your line breaks.

UPPERCASE and lowercase simply change every letter. Sentence case capitalises the first letter of each sentence and the pronoun “I”, and leaves everything else in lower case, which suits body text and many headings. Title Case capitalises the first letter of each word, which is common for headlines and book titles. Because proper nouns and acronyms are not detected, check names such as “iPhone” or “NASA” after converting.

Style guides differ on titles. Many (including AP, Chicago and APA, in different ways) keep short articles, conjunctions and prepositions such as “a”, “the”, “of”, “and” and “in” lower case unless they are the first or last word. The “Title Case (small words lower)” button applies that common rule, while the plain “Title Case” button capitalises every word. Apostrophes do not start a new word, so “don’t” becomes “Don’t”, not “Don’T”.

Code styles use case to mark word boundaries when spaces are not allowed. camelCase starts lower and capitalises each following word (userAccountId) and is common for JavaScript variables. PascalCase capitalises every word (UserAccountId) and is typical for class and component names. snake_case joins lower-case words with underscores and is standard in Python and database columns. kebab-case uses hyphens, which suits URLs, CSS class names and file names. CONSTANT_CASE uses upper-case letters with underscores for constants and environment variables.

The converter splits your input into words on spaces, punctuation and existing camel-case boundaries, so “userAccountID”, “user account id” and “user-account-id” all convert cleanly between styles.

Case conversion follows the rules of the Unicode alphabet your browser supports, so accented letters such as é and ü convert correctly. A few languages have special rules (for example the Turkish dotted and dotless I) that a general tool cannot know, so review text in those languages.

Because each button converts the current text, you can chain conversions: for example convert to lower case first and then to Sentence case to repair text that was typed with caps lock on. If you want to compare versions, copy the original somewhere first.