Case Converter

About the Case Converter

This switches text between letter cases and programming naming styles in one click. Two audiences use it constantly: writers and editors fixing headings, titles and shouty ALL-CAPS pastes; and developers converting names between the conventions different languages and databases expect — camelCase for JavaScript variables, snake_case for Python and SQL columns, kebab-case for URLs and CSS classes, CONSTANT_CASE for config keys, PascalCase for class names.

Cleaning up messy pasted text first? See Remove Extra Spaces. Specifically need a URL-safe slug rather than generic kebab-case? See Text to Slug, which also strips characters a URL can't use.

How it works — each mode

• UPPERCASE / lowercase — a straight case change of every letter.
• Title Case — capitalises the first letter of each word and lowercases the rest.
• Sentence case — lowercases everything, then capitalises the first letter of each sentence (after ., !, ?).
• camelCase / PascalCase / snake_case / kebab-case / CONSTANT_CASE — the text is first broken into words (runs of letters and digits), then rejoined with the right separator and capitalisation for that style.

The programming styles share one word-splitting rule, so "my API v2" becomes myApiV2, my_api_v2, my-api-v2, and so on, consistently.

Assumptions and behaviour

• Word boundaries are runs of letters and digits. Spaces, punctuation, underscores and symbols all act as separators, so they're dropped when building camel/snake/kebab/constant forms.
• Title and sentence case lowercase the rest of each word, so intentional inner capitals are flattened — "iPhone" becomes "Iphone", "McDonald" becomes "Mcdonald".
• Sentence case detects sentence ends by the characters ., ! and ?.

Limitations

• Accented and non-Latin letters are dropped by the programming styles. The word-splitter recognises only A–Z, a–z and 0–9, so characters like é, ñ, ü or any non-Latin script are removed when converting to camelCase, snake_case, kebab-case, PascalCase or CONSTANT_CASE. UPPERCASE, lowercase, Title and Sentence case keep them, because those operate on the whole string.
• It doesn't know proper nouns or acronyms, so Title/Sentence case won't preserve NASA or fix i to I beyond sentence starts.
• Sentence detection is punctuation-based and can be fooled by abbreviations like "e.g." or "Mr.".

Privacy

All conversion happens in your browser. Your text is never uploaded or stored.