---
# System prepended metadata

title: Difference between @mixin and @extends in SCSS

---

# Difference Between `@mixin` and `@extends` in SCSS
In this article, we will explore the key differences between `@mixin` and `@extends` in SCSS. Both are powerful tools, but they serve different purposes when it comes to reusing styles.
## What is `@mixin`?

`@mixin` allows us to create reusable chunks of CSS code that can be included in other selectors. This helps reduce redundancy and keeps our code DRY (Don't Repeat Yourself).

### Example:
```scss
@mixin button-styles($color) {
  background-color: $color;
  border-radius: 5px;
  padding: 10px 20px;
  color: white;
}

.btn-primary {
  @include button-styles(blue);
}

.btn-secondary {
  @include button-styles(green);
}
```

## What is `@extends`?
`@extends` allows one class to inherit the styles of another class, reducing the amount of duplicated code.
### Example:
```scss
.base-button {
  background-color: blue;
  color: white;
  padding: 10px 20px;
}

.btn {
  @extend .base-button;
}
```

## Key Differences Between `@mixin` and `@extends`

| Feature                    | `@mixin`                             | `@extends`                        |
|----------------------------|--------------------------------------|-----------------------------------|
| **Purpose**                 | Allows reusable chunks of CSS with customizable options | Inherits styles from another class |
| **Flexibility**             | Can accept arguments for more flexible styling | Limited to exact style inheritance |
| **CSS Output**              | Generates more CSS, but allows variations | Generates less CSS by merging selectors |
| **Use Case**                | For reusable styles with parameters (e.g., button sizes, colors) | For sharing exact styles without modification |
| **DRY Principle**           | Keeps code DRY by reusing chunks of code | Keeps code DRY by sharing existing styles |
| **Modifications**           | Styles can be modified with different arguments | No direct modification; extends the existing class |

## Conclusion

In conclusion, both `@mixin` and `@extends` play vital roles in keeping your CSS code organized, maintainable, and DRY (Don't Repeat Yourself), but they serve different purposes.

`@mixin` is ideal when you need flexibility and the ability to pass arguments to generate reusable chunks of CSS, making it more suitable for dynamic styling.

`@extends`, on the other hand, is perfect for sharing styles across multiple selectors, especially when you want to inherit existing styles without modifying them.

Understanding when to use each will help you write cleaner, more efficient code, and it will make your CSS easier to manage as your project grows.

# Understanding Block, Element, Modifier (BEM) in CSS

BEM (Block, Element, Modifier) is a popular naming convention for structuring CSS classes in a way that makes your code more maintainable and scalable.

BEM helps you create independent, reusable components, making it easier to work on large-scale projects.

## BEM Structure: Block, Element, Modifier

BEM is made up of three parts:
- **Block**: The standalone entity or component (e.g., `button`, `header`).
- **Element**: A part of the block that performs a function (e.g., `button__icon`, `header__title`).
- **Modifier**: A variation of the block or element that changes its appearance or behavior (e.g., `button--large`, `header--dark`).

### Example:
```html
<button class="button button--large">
  <span class="button__icon">Icon</span>
  Submit
</button>
```
In this example:

* `button` is the Block.
* `button__icon` is an Element within the Block.
* `button--large` is a Modifier that changes the size of the button.

## Advantages of BEM

- **Modularity**: BEM allows you to create small, independent components that can be reused easily.
- **Scalability**: As your project grows, BEM keeps your code organized, so it’s easier to maintain.
- **Clarity**: The naming convention makes it easy to understand what each class does, even for new developers joining the project.

## Benefits of BEM (Block, Element, Modifier)
The BEM methodology offers several advantages for structuring your CSS:

**Improved Readability:** BEM's naming convention makes it clear what each class represents, whether it's a block, element, or modifier. This clarity leads to more understandable code, especially in large projects.

**Reusability:** With BEM, blocks and elements are designed to be modular, allowing you to reuse them across different parts of your website without conflicts, reducing redundancy in your code.

**Avoids CSS Conflicts:** BEM helps prevent style clashes, especially in larger projects where multiple developers are working on the same codebase. The strict naming convention keeps styles scoped, reducing the chance of unintentional overrides.

**Scalability:** As projects grow, BEM provides a robust framework that scales well, ensuring that the CSS remains maintainable over time. It makes it easier to add new components without breaking existing ones.

**Separation of Concerns:** BEM encourages a clear separation between structure (blocks and elements) and appearance (modifiers), allowing for better organization and easier modifications in both the HTML and CSS.

**Ease of Maintenance:** Since each component has its own clear, descriptive class names, it's easier to maintain or refactor your code. When a bug occurs, it's simpler to pinpoint where changes should be made.

BEM helps developers achieve cleaner, more maintainable, and scalable CSS, especially in complex or large-scale projects.

## Conclusion on BEM (Block, Element, Modifier)
The BEM methodology provides a structured approach to writing clean, maintainable, and scalable CSS for modern web development. By following its systematic naming conventions, developers can avoid common issues like style conflicts and code redundancy. BEM’s focus on reusability and clarity makes it easier to collaborate on large projects, ensuring that both individual components and entire codebases remain easy to understand and maintain over time. For any team or developer working on scalable projects, BEM proves to be an essential methodology for writing effective CSS.




