UPPERCASE, camelCase, snake_case: A Guide to Text Case Styles

Different tools and languages expect text formatted in different case styles, and switching between them by hand — retyping a heading in Title Case, or renaming a variable to snake_case — is tedious and error-prone.

The common case styles

UPPERCASE / lowercase — every letter capitalized or none at all.
Title Case — the First Letter Of Each Major Word Is Capitalized, common in headings and titles.
Sentence case — only the first letter of the sentence is capitalized, like normal prose.
camelCase — words joined with no spaces, each word after the first capitalized (firstName), common in JavaScript and Java variable names.
PascalCase — like camelCase but the first word is also capitalized (FirstName), common for class names.
snake_case — words joined with underscores, all lowercase (first_name), common in Python and database column names.
kebab-case — words joined with hyphens, all lowercase (first-name), common in URLs and CSS class names.

Why the convention actually matters

Following the expected case style isn't just style preference — many languages and systems are case-sensitive, and mixing conventions (like first_Name in a codebase that expects firstName) makes code harder to read and can break tools that expect a consistent pattern (linters, auto-generated documentation, search).

How to convert text case

Paste your text into the Case Converter and choose the target case — it converts instantly, whether you're reformatting a heading or renaming a variable to match your codebase's convention.

A quick reference

Input	camelCase	snake_case	kebab-case
First Name	firstName	first_name	first-name

(Table shown here for reference — the tool itself converts free text, not just short labels.)

FAQ

Why do JavaScript and Python use different case conventions by default? It's a long-standing convention in each language's ecosystem rather than a technical requirement — following it just keeps your code consistent with the libraries and codebases developers expect to read.

Does case matter in URLs? Yes — URLs are case-sensitive on most servers, so /my-page and /My-Page can be treated as different pages. Lowercase kebab-case is the standard convention for URL slugs (docs/SEO.md #4).

Can I convert an entire paragraph, not just a single word? Yes — case conversion works on any length of text, including full paragraphs and multi-word variable names.

Convert text case now

Try the free Case Converter — supports UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case and kebab-case. See more text tools.