Case Converter

How Case Converter works

Convert text to uppercase, lowercase, title case, sentence case, camelCase, snake_case and kebab-case in one click. Everything happens inside this page: the tool reads your input, runs the calculation or conversion locally, and hands the result back to you. Nothing is transmitted, because there is no backend to transmit it to.

That design choice is deliberate. Most free tool sites upload your files to a server, process them there, and quietly keep a copy. Toolcin cannot do that — the site is a set of static files. If your connection dropped the moment the page finished loading, every tool would still work.

The nine conversions, and what each one really does

Uppercase and lowercase are the simple ones. The interesting behaviour is in the programming cases: camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE first strip everything that is not a letter or digit, then rebuild the word — so “User's full name!” becomes userSFullName rather than keeping the apostrophe.

That stripping is deliberate. Identifiers cannot contain punctuation, and silently keeping it produces a variable name that will not compile.

Title Case is not “capitalise everything”

This Title Case capitalises the first letter of every word and lowercases the rest, so “iOS” becomes “Ios” and “McDonald” becomes “Mcdonald”. That is the mechanical definition, and it is correct for headlines that are written in ordinary words.

Brand names, acronyms and CamelCase words need manual correction after the conversion. No automatic title-caser can know that “iPhone” should stay as it is.

Sentence case, and the abbreviation problem

Sentence case lowercases everything and then capitalises the first letter of the text and the first letter after a full stop, question mark or exclamation mark. Abbreviations break it: “e.g. this” becomes “E.g. This”, because the engine cannot tell a sentence break from a dotted abbreviation.

For a long document, that produces a handful of wrong capitals — faster to fix than to type by hand, but not something to publish unchecked.

Where these conversions get used

camelCase and PascalCase for JavaScript and C# identifiers, snake_case for Python and SQL columns, kebab-case for URLs and CSS classes, CONSTANT_CASE for environment variable names. Getting the convention wrong in a codebase is a small thing that reviewers notice immediately.

Good to know

• Works offline once loaded, including on flights and in locked-down networks.
• No file size limit beyond your device's own memory.
• Free to use, with no account and no usage counter.
• Results are produced locally, so they are not logged or shared with anyone.

Questions