SCSS vs Sass: Complete Guide to Differences

Sass (Syntactically Awesome Style Sheets) and SCSS (Sassy CSS) are actually two different syntax formats for the same CSS preprocessor language. SCSS is the newer syntax that’s fully CSS-compatible, while Sass uses an indentation-based syntax that’s more concise but less familiar to CSS developers. Both compile to standard CSS and share the same features, capabilities, and language foundation.

Contents

• What is Sass?
• What is SCSS?
• Key Differences Explained
• Syntax Comparison
• When to Use Each
• Migration Between Formats
• Choosing the Right Syntax

What is Sass?

Sass stands for “Syntactically Awesome Style Sheets” and was the original syntax format created by Hampton Catlin in 2006. The original Sass syntax uses indentation-based formatting similar to Python or YAML, which eliminates the need for braces and semicolons. This makes the code more concise and readable once you’re familiar with the syntax.

The original Sass syntax introduced powerful features like:

• Variables using the $ symbol
• Nested rules
• Mixins with @mixin and @include
• Math operations and functions
• Control directives like @if, @for, @each, and @while
• Inheritance with the @extend directive

However, the indentation-based syntax can be challenging for CSS developers who are used to traditional brace-based formatting.

What is SCSS?

SCSS, introduced in 2010 and sometimes referred to as “Sassy CSS,” is the newer syntax format that’s fully compatible with existing CSS code. SCSS maintains all the features of Sass but uses a syntax that’s much more familiar to CSS developers.

The key difference is that SCSS:

• Uses braces {} to declare blocks
• Requires semicolons ; to separate statements
• Can directly accept valid CSS without any conversion
• Provides a more gradual learning curve for CSS developers

SCSS was developed to address the growing need for a syntax that wouldn’t break existing CSS workflows and would be easier for developers transitioning from traditional CSS to a preprocessor.

Key Differences Explained

The primary differences between Sass and SCSS are syntactical rather than functional - they represent the same language with different writing styles:

Syntax Style

• Sass: Indentation-based, no braces or semicolons required
• SCSS: Brace-based, requires semicolons, identical to CSS syntax

CSS Compatibility

• Sass: Not directly compatible with CSS - requires conversion
• SCSS: Fully CSS-compatible - can include valid CSS directly

Learning Curve

• Sass: Steeper learning curve for CSS developers
• SCSS: Minimal learning curve for those who know CSS

File Extensions

• Sass: .sass file extension
• SCSS: .scss file extension

Developer Preference

• Sass: Preferred by developers who value conciseness and minimal syntax
• SCSS: Preferred by developers and teams transitioning from CSS or maintaining CSS compatibility

Syntax Comparison

Let’s compare how the same code looks in both formats:

Variables

Sass syntax:

$primary-color: #3498db
$font-size: 16px

body
  color: $primary-color
  font-size: $font-size

SCSS syntax:

$primary-color: #3498db;
$font-size: 16px;

body {
  color: $primary-color;
  font-size: $font-size;
}

Nested Rules

Sass syntax:

nav
  ul
    margin: 0
    padding: 0
    list-style: none
  li
    display: inline-block
  a
    display: block
    padding: 6px 12px
    text-decoration: none

SCSS syntax:

nav {
  ul {
    margin: 0;
    padding: 0;
    list-style: none;
  }
  li {
    display: inline-block;
  }
  a {
    display: block;
    padding: 6px 12px;
    text-decoration: none;
  }
}

Mixins

Sass syntax:

=border-radius($radius)
  -webkit-border-radius: $radius
  -moz-border-radius: $radius
  border-radius: $radius

.box
  +border-radius(10px)

SCSS syntax:

@mixin border-radius($radius) {
  -webkit-border-radius: $radius;
  -moz-border-radius: $radius;
  border-radius: $radius;
}

.box {
  @include border-radius(10px);
}

When to Use Each

Use Sass When:

• You’re starting a new project and prefer minimal syntax
• You’re working in teams that already use indentation-based syntax
• You value code conciseness and reduced typing
• You want to enforce a specific coding style that differs from traditional CSS
• You’re comfortable with learning new syntax patterns

Use SCSS When:

• You’re transitioning from traditional CSS
• You need to include existing CSS code without modification
• You’re working in teams with mixed CSS/Sass experience
• You prefer syntax that’s immediately recognizable to CSS developers
• You want minimal disruption to existing workflows

Industry Adoption: According to surveys and usage statistics, SCSS has become the more popular syntax in recent years, with approximately 70-80% of developers choosing SCSS over Sass for new projects.

Migration Between Formats

Converting between Sass and SCSS formats is straightforward:

Using Sass Tools

The Sass command-line tool can automatically convert between formats:

# Convert SCSS to Sass
sass input.scss output.sass

# Convert Sass to SCSS  
sass input.sass output.scss

IDE and Editor Support

Most modern code editors provide:

• Syntax highlighting for both .sass and .scss files
• Auto-formatting options for both syntaxes
• Conversion utilities through extensions or built-in tools

Best Practices for Migration

1. Gradual Conversion: Convert files incrementally rather than all at once
2. Testing: Always test compiled CSS after conversion
3. Team Coordination: Ensure all team members understand the new syntax
4. Documentation: Update style guides and documentation to reflect the chosen syntax

Choosing the Right Syntax

The choice between Sass and SCSS ultimately depends on your specific needs and context:

Project Considerations

• New Projects: SCSS is often recommended for its CSS compatibility
• Existing Projects: Match the syntax already in use
• Team Experience: Choose based on team familiarity and preferences
• Integration Needs: Consider tooling and build system requirements

Long-term Maintenance

• SCSS: Easier for new developers to understand and maintain
• Sass: More concise but may require more onboarding for CSS-experienced developers

Future Trends

While both syntaxes remain fully supported, the Sass core team has indicated that SCSS is now considered the primary syntax for new development, with most documentation and examples using SCSS syntax.

Conclusion

Sass and SCSS represent the same powerful CSS preprocessor technology with different syntax approaches. The key takeaways are:

1. Same Language, Different Syntax: Both compile to identical CSS and offer identical features - only the writing style differs
2. SCSS is CSS-Compatible: You can paste valid CSS directly into SCSS files, making it ideal for CSS developers
3. Sass is More Concise: The indentation-based syntax reduces boilerplate code but requires learning new patterns
4. SCSS Dominates Adoption: Most new projects and developers choose SCSS for its familiarity and CSS compatibility
5. Flexibility is Key: You can switch between syntaxes or even mix them in the same project if needed

For most developers starting today, SCSS offers the best balance of power and familiarity, while Sass remains a valid choice for those who prefer its minimalist approach. The choice ultimately comes down to personal preference, team standards, and project requirements rather than functional differences.

Sources

1. Official Sass Documentation
2. Sass vs SCSS Comparison
3. Sass Syntax Guide
4. SCSS Syntax Reference
5. Sass Best Practices