Sass vs SCSS: What's the Difference and Which Should You Use?

Sass vs SCSS: the short answer

Sass and SCSS are not two different tools. They are two syntaxes for the same preprocessor, which is officially called Sass. Both are compiled by the same engine (Dart Sass) and produce identical CSS. The only real difference is how the source code looks:

• SCSS (.scss) uses curly braces {} and semicolons ;, exactly like regular CSS. Any valid CSS file is already valid SCSS.
• The indented syntax (.sass) drops the braces and semicolons, using indentation and newlines to define structure instead.

For almost everyone, SCSS is the right choice in 2026. It is the syntax used in nearly every tutorial, framework, and codebase, it is a strict superset of CSS so you can paste plain CSS straight in, and the wider community means better editor support and fewer surprises. The indented syntax still works and still ships, but it is a minority style you will rarely meet on a team.

The same feature in both syntaxes

The fastest way to understand the difference is to see one snippet written both ways. Here is a nested rule with a variable and a mixin.

SCSS syntax (styles.scss):

$brand: #2d72d9;

@mixin card-padding($size) {
  padding: $size;
  border-radius: $size / 2;
}

.card {
  color: $brand;
  @include card-padding(16px);

  .title {
    font-weight: 700;
  }
}

Indented syntax (styles.sass):

$brand: #2d72d9

@mixin card-padding($size)
  padding: $size
  border-radius: $size / 2

.card
  color: $brand
  +card-padding(16px)

  .title
    font-weight: 700

Both compile to exactly the same CSS. Notice the differences in the .sass version: no braces, no semicolons, indentation defines nesting, and @include can be shortened to +. The indented syntax also uses = as a shorthand for @mixin if you want it.

Note: The $size / 2 division above is shown for illustration. In current Dart Sass, / as division is deprecated. For real projects, add @use "sass:math"; at the top of the file and write math.div($size, 2) instead. See the tooling caveats below.

Side-by-side comparison

Why the two syntaxes exist

Sass launched in 2006 with only the indented syntax, heavily inspired by Haml, a terse Ruby templating language. It was deliberately minimal: no braces, no semicolons, less to type.

That terseness turned out to be a barrier. Developers coming from CSS had to relearn how to write every rule, and pasting existing CSS never worked. So in 2010, Sass 3 introduced SCSS ("Sassy CSS") as a second, CSS-friendly syntax. Because SCSS is a superset of CSS, teams could rename a .css file to .scss and start adopting Sass features gradually, without rewriting anything. That low barrier is why SCSS became the dominant style and stayed there.

Today both syntaxes are first-class citizens in Dart Sass, the current and only actively maintained implementation. (The older Ruby Sass and LibSass/node-sass are both deprecated and should not be used on new projects.)

Which should you use?

Choose SCSS if…

• You want the safest, most transferable default. This covers the vast majority of projects.
• Your team or codebase already uses CSS and you want a smooth migration path.
• You rely on framework docs, Stack Overflow answers, or design systems — almost all of them are written in SCSS.
• You paste CSS from other sources regularly (it just works).

Consider the indented syntax if…

• You strongly prefer whitespace-significant, brace-free code (the Python or Haml aesthetic).
• You are working solo or on a codebase that already standardized on .sass.
• You value keystroke economy over broad familiarity.

There is no performance difference and no feature difference between them. Everything you can do in SCSS you can do in the indented syntax and vice versa. The decision is purely about readability, team conventions, and ecosystem fit — and on all three, SCSS usually wins.

If you are still deciding whether to use Sass at all, our What Is Sass? explainer covers the core value proposition, and the Complete Guide to Sass walks through a real setup from scratch.

Migrating a CSS file to SCSS

One of SCSS's biggest practical advantages is that adoption costs almost nothing. Because .scss is a superset of CSS, you can turn an existing stylesheet into a Sass file in three steps:

1. Rename styles.css to styles.scss. It already compiles — a plain CSS file is valid SCSS.
2. Point your build at it. Run sass styles.scss styles.css (or sass --watch during development) so the compiled output is what you actually ship to the browser.
3. Refactor gradually. Introduce variables, nesting, and mixins one section at a time. Nothing forces you to rewrite the whole file at once.

The indented syntax cannot do step one. A raw CSS file pasted into a .sass file will fail to compile because of the braces and semicolons, so every rule has to be rewritten before it works. For teams with an existing CSS codebase, that friction alone usually settles the debate.

A common workflow is to keep authored SCSS in a src/ folder and compile it into a dist/ or css/ folder that gets deployed. Never edit the compiled CSS directly — your changes would be overwritten on the next build.

Editor and ecosystem support

Both syntaxes are recognized by every major editor, but the depth of support differs:

• Syntax highlighting and IntelliSense are more mature for .scss in VS Code, WebStorm, and Sublime, simply because it is the far more common format.
• Linters like Stylelint work with both, but most shared configs and rules are authored and tested against SCSS first.
• Framework and library docs — Bootstrap and countless design systems ship their Sass sources as .scss. If you want to import and override their variables, you will be reading and writing SCSS.

None of this makes the indented syntax broken; it just means the well-trodden path is SCSS, and staying on it means fewer sharp edges.

Common misconceptions

"SCSS is newer and better than Sass." Not quite. SCSS is Sass — it is one of Sass's two syntaxes. There is no version of Sass without SCSS support. When people say "Sass vs SCSS," they almost always mean "indented syntax vs SCSS syntax."

"You have to pick one forever." You are never locked in. Because both syntaxes express the same features, you can rewrite a file from one to the other by hand, and mixing extensions across files in one project is fine — Sass compiles each file according to its extension, so a .sass file and a .scss file can @use each other freely. (Note that Dart Sass does not ship an automated .sass↔.scss translator; the old Ruby sass-convert tool is gone, and sass-migrator handles things like @import→@use upgrades, not syntax conversion.)

"The .sass syntax is deprecated." It is not. The indented syntax is fully supported in Dart Sass and receives the same features as SCSS. It is just less popular.

Tooling and modern caveats

Whichever syntax you pick, a few current realities apply:

• Use Dart Sass. Install it with npm install -D sass or via Homebrew/Chocolatey. LibSass (node-sass) is deprecated and misses newer features.
• Prefer @use and @forward over @import. The old @import rule is being phased out of Sass. New code should use the module system, which scopes variables and avoids duplicated output.
• Division uses math.div(). As shown earlier, the / operator for division is deprecated. Load the built-in math module with @use "sass:math"; and call math.div($a, $b).
• Native CSS caught up on some features. Browsers now support CSS nesting and custom properties natively. If nesting is the only reason you were reaching for Sass, read Native CSS Nesting vs Sass Nesting before adding a build step.

None of these caveats favor one syntax over the other — they apply equally to .scss and .sass files, because both run through the same compiler.

The bottom line

Sass is the preprocessor; SCSS and the indented syntax are two ways to write it. They compile to the same CSS and share every feature. Pick SCSS unless you have a specific reason not to — it is the CSS-compatible, community-standard default that will serve you well on virtually any project. Reserve the indented .sass syntax for situations where you or your team genuinely prefer brace-free, whitespace-driven code.