Case Converter

// Writing cases and code cases from the same text

Paste a heading, paragraph, variable name, or untidy mixture of separators once. The converter shows twelve results together, so you can compare uppercase, lowercase, sentence case, Title Case, alternating case, inverse case, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, and dot.case without running the text through a chain of buttons.

The writing cases keep the original spaces, line breaks, numbers, and punctuation. The code cases do a different job: they find words in spaces, punctuation, underscores, hyphens, and existing camel or Pascal case, then join those words using the requested naming convention. Symbols become boundaries in code output rather than leaking into an identifier.

// What the converter can decide, and what it cannot

Sentence case lowercases the text, then capitalises the beginning, each new line, and the first letter after a full stop, question mark, or exclamation mark. A decimal point between two numbers is kept inside the number. This is a mechanical case change, not a grammar model, so it cannot restore proper names or acronyms after lowercasing them.

Title Case here capitalises every word. It does not claim to follow AP, Chicago, APA, or another editorial style, because those guides disagree about short words, hyphenated compounds, and the title's context. Code cases also normalise acronym runs, so XMLHttpRequest becomes xmlHttpRequest rather than preserving XML as an all-capital block.

Unicode letters, accents, combining marks, and numbers are kept. Case mapping follows the browser's standard Unicode behavior without guessing a language-specific locale. Conversion is limited to 20,000 characters so twelve simultaneous results stay responsive, and every operation happens in this tab without uploading the text.

// fair questions

Does the case converter upload or save my text?

No. All twelve conversions run in your browser. The text is not sent to a server or saved between visits, and reloading the page restores the fixed sample.

Does Title Case follow AP or Chicago style?

No. It capitalises every word mechanically. Editorial styles use different rules for articles, conjunctions, prepositions, and hyphenated words, so this tool does not label one set of choices as universal.

How does it convert camelCase or PascalCase into snake_case?

It splits between lowercase or numeric characters and a following capital, and before the final capital in an acronym when a normal word follows. It then lowercases the words and joins them with underscores.

Why does punctuation disappear from camelCase and snake_case?

The code formats produce identifier-style text, so punctuation, whitespace, emoji, hyphens, and underscores act as word boundaries. They do not guarantee a valid identifier in every language; a leading number may require editing before use. The writing formats keep the original punctuation and spacing.

Does it work with accented and non-English letters?

Yes. Unicode letters, combining accents, and numbers are retained, and the browser supplies their standard upper and lower case mappings. Scripts without letter case remain unchanged.