🔤 camelCase, snake_case, kebab-case Converter

What is the Programming Case Converter?

A "case style" is a convention for joining several words into a single identifier when a language does not allow spaces in names. The differences are purely about the separator and which letters are capitalised. camelCase joins words with no separator and capitalises every word except the first (firstName). PascalCase, also called UpperCamelCase, capitalises every word including the first (FirstName). snake_case lowercases everything and joins with underscores (first_name). kebab-case (also dash-case or lisp-case) lowercases and joins with hyphens (first-name). CONSTANT_CASE, sometimes called SCREAMING_SNAKE_CASE, uppercases everything and joins with underscores (FIRST_NAME). Title Case keeps spaces and capitalises each word (First Name).

The hard part of converting is not changing the separator, it is finding the word boundaries in the first place. This tool splits the input on any run of non-alphanumeric characters (spaces, underscores, hyphens, dots, slashes) and also on camel humps: a lowercase letter or digit followed by an uppercase letter marks a new word. It also handles consecutive capitals correctly, so an acronym followed by a word such as HTMLParser splits into HTML and Parser rather than H, T, M, L, Parser. Numbers attached to letters (v2, 3d) are treated as their own tokens, which is the behaviour most style guides expect.

Which style you reach for depends on the language and the kind of name. JavaScript, Java and C# favour camelCase for variables and methods and PascalCase for classes and types. Python and Rust use snake_case for variables and functions and CONSTANT_CASE for constants. CSS classes, URL slugs and many command-line flags use kebab-case. Picking the convention your codebase already uses matters more than which one is "best": consistency is what makes names readable and searchable.

When to use it

• Renaming a variable or function from one language convention to another, for example moving a snake_case Python name into a camelCase JavaScript codebase.
• Turning a plain English label like "Max Retry Count" into a CONSTANT_CASE constant (MAX_RETRY_COUNT) or a snake_case database column (max_retry_count).
• Generating a kebab-case CSS class name or URL slug from a PascalCase component name.
• Cleaning up an identifier that mixes separators (such as user-Profile_ID) into one consistent style.
• Quickly checking how the same name looks across every convention before you commit to one in a new project.

How to use the Programming Case Converter

1. Type or paste your text or identifier into the input box.
2. The tool detects the individual words automatically from spaces, underscores, hyphens, dots and camelCase humps.
3. Read off the result in every case style: camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE and Title Case.
4. Click the Copy button next to the style you need to copy it to your clipboard.

Formula & method

Worked examples

The six case styles applied to the words "user profile id"

Common naming conventions by language

Common mistakes to avoid

• Splitting acronyms letter by letter. A naive converter turns HTMLParser into h_t_m_l_parser. The correct boundary keeps the acronym whole (HTML, Parser), so the result is html_parser. This tool detects a run of capitals followed by a capital plus lowercase and breaks there.
• Mixing conventions in one codebase. Using camelCase in some files and snake_case in others makes names harder to search and read. Pick the convention your language and project already use and apply it everywhere, the converter only helps if you stay consistent.
• Assuming kebab-case is valid as a variable name. Hyphens are subtraction in most languages, so first-name is not a legal identifier in JavaScript, Python or Java. kebab-case is for CSS classes, URL slugs and CLI flags, not in-code variable names.
• Losing digits or treating numbers oddly. Names like value2 or 3dModel sit on a boundary between letters and digits. This tool treats the number as its own token (value 2, 3 d model), which matches how most style guides and linters split them.

Glossary

camelCase

Words joined with no separator, every word capitalised except the first, for example firstName.

PascalCase

Words joined with no separator, every word including the first capitalised, for example FirstName. Also called UpperCamelCase.

snake_case

All-lowercase words joined by underscores, for example first_name.

kebab-case

All-lowercase words joined by hyphens, for example first-name. Also called dash-case.

CONSTANT_CASE

All-uppercase words joined by underscores, for example FIRST_NAME. Also called SCREAMING_SNAKE_CASE.

Word boundary

The point where one word ends and the next begins, detected from separators or a change in letter case (a camel hump).

Identifier

A name for a variable, function, class or other entity in source code.

Frequently asked questions