snake_case vs camelCase: Which Naming Convention Should You Use?
Naming conventions are one of the most debated topics in software development. Two of the most popular styles are snake_case and camelCase. Choosing the right one can make your code more readable, maintainable, and consistent. This guide breaks down the differences, when to use each, and how to convert between them.
What Is snake_case?
In snake_case, words are separated by underscores and all letters are lowercase. It is named after the way the underscores resemble a slithering snake.
Examples:
user_name, get_total_price, max_retry_count
Snake_case is the standard in Python (PEP 8), Ruby, Rust, and is commonly used for database column names. You can instantly convert text to this format with our snake_case converter.
What Is camelCase?
In camelCase, words are joined without spaces and every word after the first starts with a capital letter. The first letter is lowercase, creating humps like a camel.
Examples:
userName, getTotalPrice, maxRetryCount
CamelCase is the convention in JavaScript, TypeScript, Java, and C# for variables and function names. Convert any text to camelCase with our camelCase converter.
Side-by-Side Comparison
| Feature | snake_case | camelCase |
|---|---|---|
| Separator | Underscore (_) | Capital letter |
| Readability | High (clear word boundaries) | Good (compact) |
| Length | Longer (extra characters) | Shorter (no separators) |
| Languages | Python, Ruby, Rust, SQL | JavaScript, Java, C#, Swift |
| Use cases | Variables, functions, DB columns | Variables, functions, JSON keys |
| Accessibility | Easier for screen readers | Can be ambiguous for readers |
Which Languages Use Which Convention?
- Python: snake_case for variables and functions (PEP 8), PascalCase for classes
- JavaScript/TypeScript: camelCase for variables and functions, PascalCase for classes and React components
- Java: camelCase for variables and methods, PascalCase for classes
- Ruby: snake_case for variables, methods, and file names
- Rust: snake_case for variables and functions, PascalCase for types and traits
- Go: camelCase for unexported, PascalCase for exported identifiers
- CSS: Neither — CSS uses kebab-case for class names and properties
Readability Research
A 2010 study by Bonita Sharif and Jonathan Maletic found that snake_case identifiers were identified more quickly and accurately than camelCase ones. The underscores create clear visual word boundaries, making it easier for developers to parse long variable names at a glance.
However, camelCase is more compact and produces shorter identifiers, which some developers prefer for keeping lines of code within width limits. The best choice ultimately depends on your language's ecosystem and your team's style guide.
What About Other Conventions?
Snake_case and camelCase are not the only options. Consider these related conventions:
- PascalCase (or UpperCamelCase): Like camelCase but the first letter is also capitalized. Used for class names in most languages. Try our PascalCase converter.
- kebab-case: Words separated by hyphens. The standard for CSS, URLs, and HTML attributes. Convert with our kebab-case converter.
- CONSTANT_CASE: All uppercase with underscores. Used for constants and environment variables.
How to Convert Between Them
Switching between naming conventions manually is tedious and error-prone, especially when renaming variables across a codebase. Use our free online converters to transform text instantly:
- Paste your text into the snake_case converter or camelCase converter
- The converted result appears instantly
- Copy the output and use it in your code
Convert Between Naming Conventions
Instantly convert text to snake_case, camelCase, PascalCase, or kebab-case.
Try snake_case Converter →