Case Converter: The Ultimate Naming Convention Guide (2026)

There are only two hard things in Computer Science: cache invalidation and naming things. And part of naming things is deciding HOW to write them. Should it be userId, user_id, or UserID?

These "casing conventions" aren't just about aesthetics; they are strict standards enforced by programming languages and communities. Mixing them up (e.g., using snake_case in Java) is a surefire way to look like a novice. This guide covers every major standard you need to know.

camelCase

Format: First letter lowercase, first letter of subsequent words uppercase. No spaces or separators.

const userProfileImage = "url";
function calculateTotalScore() { ... }

Where to use it:

• JavaScript/TypeScript: Variables, Functions, Methods, and Keys in JSON.
• Java: Variables and Methods.
• Golang: Internal (unexported) variables.

snake_case

Format: All lowercase, words separated by underscores (_).

user_profile_image = "url"
def calculate_total_score():
    return 100

Where to use it:

• Python: Almost everything (variables, functions, filenames).
• SQL: Database table names (users_table) and column names (first_name).
• Rust: Variables and functions.

kebab-case

Format: All lowercase, words separated by hyphens (-). Also called "spinal-case" or "lisp-case".

.user-profile-card {
    background-color: #fff;
}
// https://example.com/blog/naming-conventions-guide

Where to use it:

• CSS: Class names, ID names, and properties.
• URLs: SEO-friendly slugs (Google prefers hyphens over underscores).
• HTML Attributes: data-user-id="123".

PascalCase

Format: First letter uppercase, first letter of subsequent words uppercase. Like camelCase, but capitalized start.

class UserProfile { ... }

// React Components MUST be PascalCase
const SubmitButton = () => <button>Go</button>;

Where to use it:

• Classes: In almost every OOP language (Java, JS, Python, C#).
• React/Vue: Component names.
• Golang: Public (exported) variables/structs.

SCREAMING_SNAKE_CASE

Format: All uppercase, words separated by underscores.

const MAX_RETRY_ATTEMPTS = 5;
const API_BASE_URL = "https://api.example.com";

Where to use it:

• Constants: Values that are hard-coded and never change during execution.
• Environment Variables: DB_PASSWORD, AWS_SECRET_KEY.

Frequently Asked Questions