Aa Case Converter
Type once and get nine cases side by side. Paste several lines to convert each line separately — perfect for renaming a whole list of variables.
How to use the case converter
- Type or paste a sentence, a headline or a variable name. All nine boxes below update at the same time.
- Press copy on the box you need — or simply click the result — to copy it.
- Paste several lines to convert each line on its own. For example, turn a list of database columns into camelCase field names in one go.
Which case should I use?
| Case | Example | Typical use |
|---|---|---|
| camelCase | userProfileImage | JavaScript, TypeScript and Java variables and functions; JSON keys |
| PascalCase | UserProfileImage | Classes, React components, C# methods and types |
| snake_case | user_profile_image | Python variables and functions, Ruby, SQL table and column names |
| kebab-case | user-profile-image | URL slugs, CSS classes, file names, npm package names |
| CONSTANT_CASE | USER_PROFILE_IMAGE | Constants and environment variables (.env) |
| Title Case | The Lord of the Rings | Book, article and song titles; headlines; buttons |
| Sentence case | The lord of the rings | Body text, UI labels, Google-style headings |
How words are split
The programming cases (camel, Pascal, snake, kebab, CONSTANT) first break the input into words, then glue them back together with the right rule. Spaces, underscores, hyphens, dots and other symbols are word boundaries — and so is a lowercase-to-uppercase change. That means maxRetryCount, max_retry_count, max-retry-count and Max Retry Count are all recognized as the same three words and can be converted into each other freely.
- Runs of capitals are treated as acronyms:
XMLHttpRequest→xml_http_request - Digits stay with the word before them:
version2Update→version2_update - Apostrophes are dropped:
don't stop→dontStop - Letters from scripts without case (Chinese, Korean, Arabic…) stay as they are; only the word separators change.
Title Case rules
English titles capitalize the major words and keep short function words lowercase: articles (a, an, the), short prepositions (of, in, on, to, for, with…) and coordinating conjunctions (and, but, or, nor). The first and last words are always capitalized. Style guides differ in the details — AP and APA capitalize every word of four letters or more (so "With" and "From" get a capital), while Chicago lowercases all prepositions regardless of length — so review important headlines. Turn off the "keep a, of, the… lowercase" option to capitalize every word (sometimes called Start Case).
Title Case and Sentence case lowercase the rest of each word, so NASA can become Nasa. Turn on "Keep acronyms in caps" to leave words of two or more capital letters untouched. Proper nouns with unusual casing (iPhone, GitHub, eBay) should be checked by hand. Nothing you type leaves your browser.