Text Case Converter

Ten cases, one input

Programming ecosystems never agreed on a single naming convention: JavaScript prefers camelCase for variables and PascalCase for classes, Python and Rust use snake_case, environment variables and constants are CONSTANT_CASE, CSS classes and URLs favor kebab-case, and config keys sometimes use dot.case. This tool converts your input into all ten common cases simultaneously — including plain lowercase, UPPERCASE, Title Case and Sentence case for prose — so renaming an identifier across languages is a copy-paste, not a mental exercise.

How the tokenizer works

Correct case conversion depends on splitting the input into words first. The tokenizer here breaks on whitespace, punctuation, underscores and hyphens, and — crucially — on camelCase boundaries: parseJSONFile becomes the tokens parse, JSON, File. Acronym runs are kept together (a lowercase letter followed by an uppercase one splits, and the last capital of an uppercase run starts a new word), so HTTPServer converts to http_server, not h_t_t_p_server. That means you can paste an identifier in any convention and get clean output in every other one.

FAQ

What's the difference between camelCase and PascalCase?

Both remove separators and capitalize word starts — the only difference is the first letter: myVariableName is camelCase, MyVariableName is PascalCase. Convention in most languages: camelCase for variables and functions, PascalCase for types, classes and React components.

When should I use kebab-case vs snake_case?

Use kebab-case anywhere hyphens are legal but underscores are awkward: URLs and slugs (search engines treat hyphens as word separators), CSS class names, CLI flags and npm package names. Use snake_case where hyphens would be parsed as a minus sign: identifiers in Python, Ruby, Rust, SQL columns and file names in many codebases.

Does Title Case here follow style-guide rules?

It capitalizes the first letter of every word, which is the simple, predictable form. Editorial styles like AP or Chicago lowercase short conjunctions and prepositions ("of", "and", "the") — if you need strict style-guide capitalization, use this output as a starting point and lowercase those small words manually.