What each case button does
The text box is edited in place: pressing a button replaces the contents with the converted version, and there is no undo, so copy your original first if you may want it back. The seven conversions behave like this.
| Style | Example output | Typical use |
|---|---|---|
| UPPERCASE | HELLO WORLD | Acronyms, constants, shouting in captions |
| lowercase | hello world | Normalising emails, tags and search terms |
| Title Case | Hello World | Headings, article and book titles |
| Sentence case | Hello world. It works. | Fixing text typed with caps lock on |
| camelCase | helloWorld | JavaScript, Java and Swift variables |
| snake_case | hello_world | Python, Ruby and SQL column names |
| kebab-case | hello-world | URLs, CSS classes, file names |
How the conversions work
UPPERCASE and lowercase use the browser's built-in Unicode-aware conversion, so accented letters convert correctly and the German ß becomes SS in upper case. Title Case capitalises the first letter of every word and lower-cases the rest. It does not know about style guides, so small words like "of", "the" and "and" are capitalised too. If you follow AP or Chicago style, fix those by hand afterwards.
Sentence case first lower-cases everything, then capitalises the first letter of the text and any letter that follows ., ! or ?. That means proper nouns and the pronoun "I" are lower-cased and need re-capitalising.
The three programmer styles first extract words, which are runs of the letters A to Z and the digits 0 to 9, and then join them. Everything else is treated as a separator and discarded, including punctuation, apostrophes and accented letters.
Worked example
Input: Hello, World-wide web 2024
- snake_case gives
hello_world_wide_web_2024 - kebab-case gives
hello-world-wide-web-2024 - camelCase gives
helloWorldWideWeb2024 - Title Case gives
Hello, World-wide Web 2024
Limits to know about
- Existing camelCase is not split.
userAccountIDis read as a single word, so snake_case returnsuseraccountid. Add spaces first if you are converting between code styles. - Because only ASCII letters count as word characters,
café menubecomescaf_menuin snake_case. Transliterate accents first if you need them kept. - Title Case treats an apostrophe as part of a word, so
don'tbecomesDon't, notDon'T.
For URL-ready strings that also strip accents and punctuation, the text to slug tool is the better fit. For decorative lettering rather than real case changes, see the fancy text generator.