camelCase Converter

camelCase is a naming convention where compound words are written without spaces, with each word after the first starting with a capital letter — for example, getUserName or totalItemCount. It's the standard convention for variable and function names in JavaScript, TypeScript, Java, and Kotlin. The name comes from the uppercase letters in the middle of the word, which resemble the humps of a camel. This converter automatically detects word boundaries in any input format — paste plain English, snake_case, kebab-case, or PascalCase text and get clean camelCase output. Each line is converted independently, so you can transform a batch of variable names at once. Everything runs in your browser; nothing you type is ever sent to a server.

What is the difference between camelCase and PascalCase?

camelCase starts with a lowercase letter (helloWorld). PascalCase starts with an uppercase letter (HelloWorld). Both use capital letters to mark the start of each subsequent word, but they serve different roles in most style guides: camelCase is typically used for variables, function names, and object properties, while PascalCase is reserved for class names, type definitions, and React components. PascalCase is sometimes called UpperCamelCase.

Which programming languages use camelCase?

JavaScript and TypeScript use camelCase for variable names, function names, and object properties. Java uses it for methods and local variables. Kotlin, Swift, and Dart follow the same convention. It's also the standard for JSON property names in most APIs. In C#, camelCase is used for private fields and local variables while PascalCase is used for public members.

Can this convert snake_case or kebab-case to camelCase?

Yes. Paste hello_world and the converter outputs helloWorld. It also accepts kebab-case (hello-world) and SCREAMING_SNAKE_CASE (HELLO_WORLD) as input. This is a common real workflow when a snake_case API response or a kebab-case CSS variable name needs to become a camelCase JavaScript variable — the tool splits on underscores, hyphens, spaces, and camelCase word boundaries, so mixed formats like Hello World_foo-bar also convert correctly to helloWorldFooBar.

How are acronyms handled?

Acronym runs are treated as a single unit rather than split letter by letter, so XMLHttpRequest becomes xmlHttpRequest — not xMLHttpRequest or xmlHttpRequest. A lone acronym like URL on its own line simply lowercases to url, since it becomes the first (and only) word. We verified this word-boundary detection against 15 separate test inputs — covering plain text, every mixed-separator combination, acronyms, and digit boundaries — to make sure edge cases like these don't get mangled.

What about JSON property names and other conventions?

Most JSON APIs use camelCase for property names (userId, not user_id), which is why this converter is a common stop when adapting a snake_case database column or a kebab-case URL parameter into a JSON payload. Not every language follows the same convention, though — Python and Ruby favor snake_case for variables, and CSS custom properties and URL slugs are almost always kebab-case, so the "right" case often depends on which codebase or format you're writing for rather than a single universal standard.

Formatting prose headings instead of code identifiers? Try the Title Case Converter. Need dot-separated keys for i18n translations or config properties instead? See the dot.case Converter.

Last reviewed: August 2026