Snake_case vs Kebab-case Converter: Naming Convention Tool

snake_case (with underscores) and kebab-case (with hyphens) are two of the most common separator-based naming conventions in programming. Both serve the same purpose — making multi-word identifiers readable — but they're used in different contexts.

The choice between them isn't arbitrary. Different technologies and communities have established conventions based on technical constraints, readability, and tradition. Using the wrong convention can make your code look out of place or even cause technical issues (like broken URLs or CSS selectors).

This tool helps you convert between conventions instantly, compare them side by side, and understand when to use each based on real-world examples and best practices from major programming communities.

Python programming: The official Python style guide (PEP 8) recommends snake_case for variable names, function names, and method names. Example: calculate_user_score, is_valid_email.

Ruby programming: Ruby uses snake_case for method names and variable names. Example: find_user_by_email, maximum_retry_count.

Database design: SQL databases (PostgreSQL, MySQL) commonly use snake_case for table and column names. Example: user_profile table with created_at column.

Unix/Linux filenames: While not required, snake_case is common for script and configuration filenames. Example: setup_database.sh, config_settings.yaml.

Configuration files: Many config formats (YAML, TOML, .env files) use snake_case for keys. Example: api_base_url, max_connection_pool.

URLs and URL slugs: Hyphens are URL-safe and recommended by Google for SEO. Example: https://example.com/user-profile-picture.

CSS class names and IDs: The CSS specification allows hyphens but treats underscores as part of the identifier name. Example: .user-profile-picture, #main-navigation.

npm package names: The npm registry requires lowercase names and recommends kebab-case. Example: react-router-dom, express-validator.

HTML attributes: Custom data attributes must use kebab-case. Example: data-user-profile-id, aria-describedby.

Command-line tools: Many CLI tools use kebab-case for commands and options. Example: git commit --amend, docker-compose up.

1. Follow the language/framework conventions.When in Rome, do as the Romans do. If you're writing Python, use snake_case. If you're writing CSS, use kebab-case. Consistency with the ecosystem matters more than personal preference.

2. Consider technical constraints.Some systems have hard requirements: CSS selectors work with hyphens, URLs should use hyphens for SEO, some databases are case-insensitive.

3. Be consistent within your project.Pick one convention per context (e.g., snake_case for Python code, kebab-case for URLs) and stick to it throughout the project. Mixed conventions create confusion.

4. Think about readability.The whole point of these conventions is to make multi-word names readable. Choose the convention that makes your code most readable for your team and tools.

5. Document your choices.If your project uses non-standard conventions (like camelCase in Python), document why in your README or contributing guidelines to help new developers.