Case Converter

The simple cases are simple: upper and lower apply the browser's own Unicode-aware conversion, so Turkish, Greek and Cyrillic letters behave correctly rather than being mangled by a Latin-only assumption.

Title case is where tools disagree with each other. Capitalising every word is the naive approach and reads wrong to an editor. Real title case keeps short joining words — a, an, and, of, the, to and friends — lowercase unless they are the first or last word. That is what this tool does, following the convention shared by most English style guides.

The programming cases — camel, Pascal, snake, kebab and constant — need to find word boundaries in text that may not have spaces. The tool inserts a break wherever a lowercase letter is followed by an uppercase one, so parseHTTPResponse is understood as three words, then splits on anything that is not a letter or digit.

All of it happens as you type, in your browser. Nothing is uploaded, which is worth knowing when the text you are reformatting is a customer list or an internal document.

You have a spreadsheet column of product names that arrived in shouting capitals: WIRELESS KEYBOARD AND MOUSE SET.

Paste it and choose Title Case. The result is Wireless Keyboard and Mouse Set — note that and stayed lowercase. Choose Sentence case instead and you get Wireless keyboard and mouse set, which is what most product catalogues actually use.

Now a developer case. You have a field label, Customer Email Address, and you need it as a JSON key. Choose camelCase for customerEmailAddress, or snake_case for customer_email_address if your API uses that convention.

A detail worth seeing. Paste parseHTTPResponse and choose kebab-case. A naive converter gives parsehttpresponse; this one gives parse-http-response, because it splits on the lowercase-to-uppercase transition before lowering anything.

If you are converting a title for a URL, the slug generator does the whole job including folding accents and trimming length.