snake_case vs kebab-case

What is snake_case?

snake_case is a naming convention where words are written in lowercase and separated by underscores (_). It's called "snake" because the underscores create a long, low appearance resembling a snake.

Examples of snake_case:

• first_name
• user_email_address
• calculate_total_price
• is_user_logged_in

What is kebab-case?

kebab-case (also called dash-case or hyphen-case) is a naming convention where words are written in lowercase and separated by hyphens (-). It's called "kebab" because the hyphens resemble skewers through meat on a kebab.

Examples of kebab-case:

• first-name
• user-email-address
• calculate-total-price
• is-user-logged-in

Key Differences

When to Use snake_case

Use snake_case for:

• Python code: def get_user_data():
• Ruby code: user_email = "test@example.com"
• Database columns: SELECT user_id, email_address FROM users
• Environment variables: DATABASE_URL
• Constants in Python: MAX_UPLOAD_SIZE = 1024

When to Use kebab-case

Use kebab-case for:

• URLs: example.com/user-profile
• CSS class names: class="user-profile-card"
• HTML attributes: data-user-id="123"
• File names: user-profile-component.tsx
• Git branch names: feature/user-authentication

Why kebab-case for URLs?

kebab-case is preferred for URLs because:

1. SEO-friendly: Search engines recognize hyphens as word separators
2. Readability: Easier to read in browser address bars
3. No special encoding needed: Underscores must be URL-encoded (%5F)
4. Google recommendation: Google explicitly recommends hyphens over underscores

Why snake_case in Programming?

snake_case works in programming because:

1. Valid identifier: Underscores are allowed in variable names
2. No operator confusion: Hyphens are minus operators in most languages
3. Language convention: Python, Ruby, and others use it as standard
4. Database-friendly: Works well in SQL without quotes

Language-Specific Conventions

Python

# snake_case for variables and functions
user_email = "john@example.com"
def get_user_data():
    return user_data

CSS

/* kebab-case for class names */
.user-profile-card {
  background-color: white;
}
.email-input-field {
  border: 1px solid gray;
}

URLs

<!-- kebab-case for URLs -->
https://example.com/user-profile
https://example.com/blog/snake-case-vs-kebab-case
https://example.com/product-details/blue-widget

Common Mistakes to Avoid

• ❌ Using snake_case in URLs: example.com/user_profile
• ❌ Using kebab-case in Python: user-email = "test@example.com" (syntax error)
• ❌ Mixing conventions: user_Email-Address
• ❌ Using spaces: user profile data (not a naming convention)

Best Practices

1. Be consistent: Choose one and stick with it in the same context
2. Follow conventions: Use snake_case for Python, kebab-case for URLs
3. Consider SEO: Always use kebab-case for URLs
4. Use lowercase: Both conventions use all lowercase letters

Quick Conversion

Need to convert between snake_case and kebab-case? Try our free converter:

Conclusion

Both snake_case and kebab-case are valuable naming conventions. Use snake_case for programming (especially Python) and database columns. Use kebab-case for URLs, CSS classes, and file names. The choice depends on the context and language conventions.