Snake Case

Snake case joins lowercase words with underscores (e.g., user_name); it is common in Python, database column names, and JSON.

Purpose

Provides a readable multi-word identifier naming style suited to case-insensitive environments.

Mechanism

Lowercase the words and join them with underscores. For example, "UserName" → "user_name". Common for Python, Ruby, SQL, and C function names. Similar to kebab-case (hyphens) but with underscores.

Use cases

Python variable and function names
Database column names
JSON key names
C/Rust function names

Examples

Input
```
UserName
```
Output
```
user_name
```
Joined with underscores

Common errors

Mixing with kebab-case causes inconsistent style: Standardize the naming style across the project

Related terms

Camel Case

Camel case joins multi-word identifiers with capitalized initials (e.g., userName or UserName); it is common in Java, JavaScript, and TypeScript.

GLOSSARY

Related tools

Case Converter

Convert text between upper, lower, title, camel, pascal, snake, kebab, constant, and sentence cases. Free, private, and 100% client-side.

TOOL

Naming Convention Converter

Convert between camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE. Free, private, 100% client-side.