Case Converter

The cases, and where each is used

UPPERCASE and lowercase are self-explanatory, and useful for normalising text before comparison or fixing something typed with caps lock on.

Title Case capitalises the first letter of every word. Used for headings, titles, and headlines. Note that editorial title case — where short words like "a", "of", and "the" stay lowercase — varies between style guides, so this tool uses the simpler rule of capitalising every word. If you're following a specific style guide, adjust the small words by hand.

Sentence case capitalises the first letter of each sentence and lowercases the rest. It's the standard for body text, and increasingly for headings too, since it reads more naturally than title case.

camelCase starts lowercase and capitalises each subsequent word, with no separators: getUserName. It's the convention for variables and functions in JavaScript, Java, and several other languages.

PascalCase is the same but starts with a capital: GetUserName. Conventionally used for class and type names, and for functions in some languages like C#.

snake_case joins lowercase words with underscores: get_user_name. The convention in Python, Ruby, and for database column names.

kebab-case joins lowercase words with hyphens: get-user-name. Standard for URLs, CSS class names, and file names — hyphens are preferred over underscores in URLs because search engines treat them as word separators.

CONSTANT_CASE is uppercase words joined by underscores: MAX_RETRY_COUNT. Used for constants and environment variables across most languages.

dot.case joins lowercase words with full stops: get.user.name. Seen in configuration keys and some namespacing conventions.

How the conversion handles existing formatting

Converting hello world is easy. The harder part is converting text that's already in some case — turning getUserName into get_user_name means correctly identifying where one word ends and the next begins.

This tool splits input on spaces, underscores, hyphens, dots, and capital-letter boundaries, so it handles text in any of the supported cases as input, not just plain words.

Acronyms are the tricky case. parseJSONData should become parse_json_data, not parse_j_s_o_n_data — so consecutive capitals are treated as a single unit, with the last capital belonging to the following word when one follows. XMLHttpRequest splits correctly into XML, Http, and Request.

Line breaks are preserved, so you can paste a list and get a converted list back rather than everything collapsed onto one line.

Common uses

• Renaming variables between languages. Moving code between a camelCase language and a snake_case one means converting every identifier — quick here, tedious by hand.
• Creating URL slugs. Turning an article title into kebab-case gives you a clean, readable URL.
• Fixing capitalisation mistakes. Text typed with caps lock on, or a heading that needs to match a style guide.
• Normalising data. Converting a column of mixed-case entries to a consistent case before comparing or importing them.
• Database and API naming. Converting between the naming convention of an API response and the one your codebase uses.

Frequently asked questions

Is my text sent to a server?

No. Conversion happens entirely in your browser. Nothing you type is uploaded or stored.

Does it handle text that's already in camelCase or snake_case?

Yes. The tool detects word boundaries from capital letters and from underscores, hyphens, and dots, so you can convert from any supported case to any other.

Why doesn't Title Case leave small words lowercase?

Editorial title case rules differ between style guides — some lowercase "of" and "the", others don't, and the exact list varies. Rather than guess at which guide you're following, this tool capitalises every word, leaving you to adjust as needed.

Does it preserve line breaks?

Yes. Multi-line input stays multi-line, so you can convert a list without it collapsing into a single line.

Does it work with accented characters and non-English text?

Yes. Accented characters and other scripts are converted correctly rather than being stripped or mangled.

Is there a limit on how much text I can convert?

No fixed limit. Very long text may take a moment, since everything is processed on your device.

Is it free?

Yes, completely free with no sign-up.