camelCase vs snake_case vs PascalCase — When to Use Each

Every programming language has a preferred way to name things. Here's when to use camelCase, snake_case, PascalCase, and kebab-case.

camelCase

First word lowercase, every next word capitalized. No spaces or separators.

myVariableName, getUserData, isLoggedIn

Used in: JavaScript, Java, TypeScript, C#, Swift

Used for: variables, function names, method names

PascalCase

Every word capitalized, including the first. Also called UpperCamelCase.

MyClassName, UserProfile, HttpRequest

Used in: JavaScript (classes), C# (classes, methods), Java (classes), TypeScript

Used for: class names, component names, type names

snake_case

All lowercase with underscores between words.

my_variable, user_name, get_user_data

Used in: Python, Ruby, Rust, SQL, PHP

Used for: variables, functions, file names, database columns

CONSTANT_CASE

All uppercase with underscores. Also called SCREAMING_SNAKE_CASE.

MAX_SIZE, API_KEY, DATABASE_URL

Used in: all languages

Used for: constants, environment variables, config values

kebab-case

All lowercase with hyphens between words.

my-component, user-profile, main-content

Used in: HTML, CSS, URLs, file names

Used for: CSS classes, URL slugs, HTML attributes

Quick Reference

• JavaScript variable? camelCase
• JavaScript class? PascalCase
• Python anything? snake_case
• CSS class? kebab-case
• Constant? CONSTANT_CASE
• URL slug? kebab-case
• Database column? snake_case

Need to convert between these formats quickly? Use our free case converter tool. Paste your text, click the format you need, and copy.