snake_case Converter — Convert Text to snake_case Online
What is snake_case?
snake_case is a naming convention where words are written in all lowercase and separated by underscores. The name comes from the appearance of the underscores as a snake crawling between the words. There are no capital letters in standard snake_case — it is entirely lowercase.
snake_case is the dominant naming convention in Python, where the official PEP 8 style guide mandates its use for variable names, function names, method names, and module names. It is also the standard in Ruby, Rust, and many other languages. Database column names are almost universally snake_case across SQL databases (PostgreSQL, MySQL, SQLite).
The underscore separator is highly readable because it creates a clear visual boundary between words at a glance, without requiring a case shift. This readability advantage makes snake_case popular for long, descriptive variable names where clarity matters more than brevity.
Example
| Input | Output (snake_case) |
|---|---|
| Hello World Variable | hello_world_variable |
How to Convert to snake_case
- Paste your text — can be a phrase, a heading, a column name, or any multi-word identifier.
- Click snake_case.
- Copy the result directly into your Python code, SQL schema, or configuration file.
The converter lowercases all characters and replaces spaces with underscores. For best results, start with plain space-separated words.
When to Use snake_case
Use snake_case whenever you're writing Python code, SQL queries, or working in any context that follows Python/Ruby conventions. It's also widely used for environment variable names (though SCREAMING_SNAKE_CASE is more common for those), for file names in projects that avoid spaces, and for configuration keys in YAML, TOML, and INI files.
Common Use Cases for snake_case
- Python variable, function, and method names (PEP 8 standard)
- Database column names in SQL (PostgreSQL, MySQL)
- Ruby variable and method names
- Rust variable and function names
- YAML and TOML configuration keys
- File and directory names in Python projects
Frequently Asked Questions
What is snake_case?
snake_case is a naming convention where all letters are lowercase and words are separated by underscores. Example: "my variable name" becomes "my_variable_name". Standard in Python, Ruby, Rust, and SQL.
What is the difference between snake_case and camelCase?
snake_case uses underscores to separate words, all in lowercase: "my_variable". camelCase uses capitalisation, no underscores: "myVariable". Python and databases prefer snake_case; JavaScript and Java prefer camelCase.
What is SCREAMING_SNAKE_CASE?
SCREAMING_SNAKE_CASE (also called CONSTANT_CASE) is snake_case with all letters uppercase. It is conventionally used for constants and environment variables in many languages. Example: MAX_RETRIES, API_BASE_URL.
Is snake_case readable?
Yes — many developers find snake_case the most readable naming convention for long identifiers because the underscores create clear, unambiguous visual word breaks. Research on code readability often favors snake_case for comprehension speed.