How does it know where one word ends and the next begins?

It looks for the boundaries every common style already marks: an underscore, hyphen, dot or space, and (for already-camelCased or PascalCased input) a lowercase letter followed by an uppercase one. Acronym runs are handled too: XMLHttpRequest tokenises as XML , Http , Request , not one letter at a time.

Is this the same as the Title Case Converter?

No. The Title Case Converter capitalises prose headlines by a style guide's rules (which small words like "a" or "of" stay lowercase). This tool tokenises a single identifier and rebuilds it in a programming case style; neither tool applies the other's rules.

What happens to acronyms and numbers?

Numbers stay attached to whichever word they touch: 2FastCars tokenises as 2 , Fast , Cars , so it converts as expected. Mixed brand-style casing like iOS has no reliable rule to detect automatically: iOS9Update tokenises as i , OS9 , Update , which is close but not perfect; check the result before using it verbatim.

Does it convert a whole file, or one identifier at a time?

A list, one identifier or phrase per line: each line is converted on its own and the results stay one per line, so a column of database field names comes back as a column of camelCase names. Blank lines and lines with no letters or digits are skipped. It does not rewrite identifiers inside source code, though: paste the names themselves, not a whole file of code.

Code Case Converter: camelCase, snake

How to use

Paste an identifier or short phrase (from camelCase, snake_case, kebab-case, plain words, or any mix), or a whole list, one per line: each line is converted on its own.
Read the six results: camelCase, PascalCase, snake_case, CONSTANT_CASE, kebab-case and dot.case, computed together from the same word boundaries. Each row says where that style is conventionally used, if you are not sure which one you need.
Press Copy on a row (Copy all for a list, one per line).
Load sample inserts a worked example; Clear empties the box.

One phrase, every case style at once

Programming languages and style guides disagree on how to write a multi-word name: JavaScript variables are camelCase, classes are PascalCase, Python and database columns are snake_case, environment variables and constants are CONSTANT_CASE, URLs and CSS classes are kebab-case, and config keys sometimes use dot.case. Converting between them by hand is mechanical and easy to get subtly wrong around acronyms and numbers; this tool does the tokenising once and shows every style at the same time.

Example

The phrase userFirstName becomes:

userFirstName
UserFirstName
user_first_name
USER_FIRST_NAME
user-first-name
user.first.name

Reading the result

camelCase: first word lowercase, each following word capitalised, no separator. The JavaScript/Java/C# convention for variables and function names.
PascalCase: every word capitalised, no separator. The convention for classes, types and React components.
snake_case: all lowercase, joined by underscores. Python's convention for variables and functions, and common for database columns.
CONSTANT_CASE: all uppercase, joined by underscores. The convention for constants and environment variables.
kebab-case: all lowercase, joined by hyphens. The convention for URLs, CSS class names and command-line flags.
dot.case: all lowercase, joined by dots. Seen in some config file keys and namespaced identifiers.

Edge cases and common errors

No recognisable words. Input made only of separators, like ___---..., has nothing to tokenise and shows an error rather than six empty boxes.
Already in the target style is a no-op. Converting userFirstName to camelCase returns userFirstName unchanged; the tool tokenises first and rebuilds, so a correctly-cased input round-trips exactly.
Acronyms next to a lowercase letter split correctly (getUserID → get, User, ID), but brand-style casing with no lowercase-to-uppercase rule to detect, like iOS, does not. See the FAQ.
A single word with no boundary is unaffected by camelCase, snake_case or kebab-case (there is nothing to split or join), but CONSTANT_CASE and PascalCase still change its letter case.
Non-Latin letters and emoji are kept as their own token (split at the nearest separator) rather than dropped, but the acronym/camelCase boundary detection only understands the Latin-letter case rules used above; mixed-script identifiers may need a manual check.

Do the same thing in code

// lodash
_.camelCase('user_first_name');   // 'userFirstName'
_.snakeCase('userFirstName');     // 'user_first_name'
_.kebabCase('userFirstName');     // 'user-first-name'

# Python
"user_first_name".title().replace("_", "")  # crude PascalCase, no acronym handling

Most languages' standard libraries do not include a full case converter: lodash (JavaScript) is the closest widely-used equivalent, and even it does not handle every acronym case this tool does.

Runs entirely in your browser: this page is a static file with no server behind it, so nothing you paste can be uploaded. Last reviewed 25 September 2026 by Parthesh Gupta.