camelCase, snake_case and kebab-case: Which Naming Style to Use

Oct 21, 2026 · 2 min read · Developer

When you name a variable with more than one word, you cannot use spaces. Programmers solved this in a few different ways, and each style has its own home.

The common styles

• camelCase: userFirstName. The first word is small, later words start with a capital. Used in JavaScript, Java and Swift variables.
• PascalCase: UserFirstName. Every word starts with a capital. Used for classes and components.
• snake_case: user_first_name. Words joined by underscores. Python, Ruby and database columns love it.
• kebab-case: user-first-name. Words joined by dashes. Common in URLs and CSS.
• CONSTANT_CASE: MAX_RETRY_COUNT. All capitals for values that never change.

Why it matters

Using the style your language expects makes code easier for others to read. It is also a matter of correctness in some places. A CSS property written as backgroundColor will not work, it must be background-color. Meanwhile in JavaScript, background-color is not a valid variable name because the dash looks like a minus sign.

When you have to convert

You will need to convert names when sending data between systems. A Python backend may return first_name, while your JavaScript front end wants firstName. Or you may be turning a page title into a URL slug, from "My First Post" into my-first-post.

Watch out for acronyms

How should "HTTP response code" look in camelCase? Some write httpResponseCode, others HTTPResponseCode. Pick one rule and keep it across the project. Our converter treats the acronym as one word, so you get httpResponseCode.

Tips for good names

• Prefer clear names over short ones.
• Do not mix styles inside one project.
• Follow the guide for your language or team.

Convert in one click

Try the Naming Case tool on our Developer Converters page. Type a name or a phrase, even one that already has underscores or dashes, and you see all five styles at once, ready to copy.

Frequently asked questions