snake_case Converter
Convert text to snake_case used in Python, Ruby, and database column names.
What is snake_case?
snake_case writes all words in lowercase and separates them with underscores. It was popularized by Python and is now the dominant naming convention in Python, Ruby, database schema design, and many system-level languages.
hello world example→hello_world_exampleWhen to Use snake_case
Use snake_case for all Python code per PEP 8, database column names (e.g., first_name, created_at), Ruby methods, PHP variables, and Rust functions. It is highly readable because spaces are clearly visible as underscores.
Do not use snake_case for JavaScript (use camelCase), CSS class names (use kebab-case), or class/type names in any language (use PascalCase). In Python, PascalCase is still used for class names.
Industry Standard
PEP 8 — the official Python style guide — mandates snake_case for all function names, variable names, and module names. PostgreSQL, MySQL, and SQLite all recommend snake_case for table and column names. The Rust programming language style guide also requires snake_case for functions and variables.
How to Use This snake_case Converter
- Paste or type your text into the Input Text box on the left.
- The output is converted to snake_case instantly on the right.
- Click Copy to copy the result to your clipboard.
- Use Clear to reset and convert new text.
snake_case in Programming Languages
def get_user_name():def get_user_namefn get_user_name() -> String$user_name = 'John';SELECT first_name FROM users;Frequently Asked Questions
Is this snake_case converter free?
Yes, completely free — no signup, no account, no limits.
Does my text get stored or sent anywhere?
No. All conversions happen entirely in your browser using JavaScript. Your text never leaves your device and is never sent to any server.
When should I use snake_case?
Use snake_case for all Python code per PEP 8, database column names (e.g., first_name, created_at), Ruby methods, PHP variables, and Rust functions. It is highly readable because spaces are clearly visible as underscores.
Expert tip
Database column names in snake_case (e.g., user_id, created_at) are a best practice because SQL is case-insensitive and snake_case columns map cleanly to Python/Ruby model attributes without any transformation needed.