Foundation vs Semantic UI

When it comes to building modern, responsive websites, developers have a plethora of CSS frameworks at their disposal. Two popular options are Foundation and Semantic UI, each with its own set of features, philosophies, and communities. In this article, we’ll delve into an in-depth comparison of these two frameworks, covering everything from their design principles to code samples, to help you decide which is best suited for your next project.

What is Foundation?

Foundation is a responsive front-end framework developed by ZURB, a product design company. It is designed to be a professional choice for designers and developers, offering a range of tools to create responsive, mobile-first websites with ease. Foundation is known for its flexible grid system, a wide array of UI components, and extensive customization capabilities.

Popular Addons for Foundation:

  • Motion UI: A library for creating custom CSS transitions and animations.
  • Foundation Building Blocks: A set of pre-made components that can be combined and customized to build unique layouts.

What is Semantic UI?

Semantic UI is a development framework that helps create beautiful, responsive layouts using human-friendly HTML. It emphasizes readable and semantic markup, allowing developers to understand the code quickly. Semantic UI comes with a rich set of elements, collections, views, modules, and behaviors that give you the power to build complex layouts without compromising on the readability of your markup.

Popular Addons for Semantic UI:

  • Semantic UI React: The official React integration for Semantic UI.
  • Semantic UI Fomantic-UI: A community fork of Semantic UI with additional features and regular updates.

Grid Systems and Responsiveness

Both Foundation and Semantic UI offer grid systems that are designed to create responsive layouts, but they approach grid implementation differently.

Foundation Grid System

Foundation’s grid is a mobile-first, flexible grid that can scale out to an arbitrary size (defined by the max width of the row) that is conducive to your specific project. It utilizes rows and columns, making it easy to create layouts that work on any device.

<div class="grid-container">
  <div class="grid-x grid-margin-x">
    <div class="cell small-6 medium-4 large-2">
      <!-- Content goes here -->
    <div class="cell small-6 medium-8 large-10">
      <!-- Content goes here -->

This code snippet demonstrates the use of Foundation’s grid system, where grid-container is the wrapper, grid-x sets up the horizontal grid, and grid-margin-x adds gutters. The cell class defines the grid item, with size classes like small-6, medium-4, and large-2 dictating how much of the grid the item should occupy on different screen sizes.

Semantic UI Grid System

Semantic UI’s grid system is similarly responsive, using a column approach that is divided into up to 16 columns per row. It also allows for nested grids, column doubling, and stackable grids.

<div class="ui grid">
  <div class="four wide column">
    <!-- Content goes here -->
  <div class="twelve wide column">
    <!-- Content goes here -->

In this example, the ui grid class is used to create a container for the grid, with child elements like four wide column and twelve wide column specifying the width of each column within the grid. The class names are self-explanatory, making the code more readable.

UI Components and Elements

Both frameworks offer a comprehensive set of UI components, but they have different collections and naming conventions.

Foundation Components

Foundation provides a robust set of UI components, including but not limited to:

  • Navigation (Top Bar, Menu, Off-canvas)
  • Buttons (Button Groups, Dropdown Buttons)
  • Forms (Input Fields, Switches, Sliders)
  • Containers (Accordion, Tabs, Modal)
  • Media Objects (Orbit Slider, Thumbnail, Badge)
<button class="button">Default Button</button>
<button class="button success">Success Button</button>
<button class="button alert">Alert Button</button>

The buttons in Foundation are styled using the button class, with additional classes like success and alert to indicate different button styles.

Semantic UI Elements

Semantic UI categorizes its components into elements, collections, views, modules, and behaviors. Some of its elements include:

  • Buttons (Social, Animated, Labeled)
  • Containers (Segment, Item, Message)
  • Dividers (Vertical, Horizontal, Hidden)
  • Headers (Page Headers, Content Headers)
  • Inputs (Text, Checkbox, Radio)
<button class="ui button">Click Here</button>
<button class="ui primary button">Primary</button>
<button class="ui secondary button">Secondary</button>

Semantic UI buttons are created using the ui button class, with additional classes like primary and secondary to modify the appearance.

Customization and Theming

Customization is a crucial aspect when choosing a CSS framework, as it allows you to tailor the look and feel of your website to match your brand identity.

Foundation Customization

Foundation is highly customizable through the use of Sass variables. You can easily change the color palette, fonts, and other styling options by modifying the _settings.scss file.

// Example of customizing Foundation with Sass
$primary-color: #ff6f61;
$secondary-color: #ffcc00;
$alert-color: #cc4b37;
$success-color: #3adb76;

// Import Foundation
@import 'foundation';

Semantic UI Theming

Semantic UI has a powerful theming system that allows you to build your theme by adjusting variables and overriding styles. It uses a special folder structure (src/themes/) where you can place your theme configurations.

// Example of Semantic UI theme.config file
@siteFolder  : 'default';
@buttonFolder: 'my-theme';

// Import Semantic UI
@import 'semantic-ui';

In this theme.config file, you can specify which theme to use for each component, such as using the default theme for the site and my-theme for buttons.

Performance and Load Times

Performance is a key factor in the user experience of any website. Both Foundation and Semantic UI have different approaches to how they affect performance.

Foundation Performance

Foundation is built with a mobile-first approach, which often means better performance on mobile devices as the CSS is structured to load the minimal necessary styles first. Additionally, Foundation allows you to include only the components you need, which can greatly reduce the overall file size.

<!-- Example of including only necessary components in Foundation -->
<link rel="stylesheet" href="css/foundation.min.css">
<script src="js/vendor/what-input.js"></script>
<script src="js/vendor/foundation.min.js"></script>

By selectively including JavaScript components, you can ensure that only the necessary scripts are loaded, improving page load times.

Semantic UI Performance

Semantic UI’s theming capability is comprehensive, but it can lead to larger file sizes if not managed properly. However, Semantic UI also allows for custom builds where you can select only the components you need.

<!-- Example of a custom build in Semantic UI -->
<link rel="stylesheet" href="css/semantic.min.css">
<script src="js/semantic.min.js"></script>

Creating a custom build with only the required components can help reduce the impact on performance.

Community Support and Resources

The strength of a framework’s community can be critical, especially when you need help troubleshooting issues or when looking for resources and plugins.

Foundation Community

Foundation has a strong community with a wealth of resources available for developers:

  • Forums: The Foundation forum is a place to discuss issues and share knowledge.
  • Building Blocks: A library of pre-built components that can be used as a starting point.
  • ZURB University: Offers training and courses to learn Foundation in-depth.

Semantic UI Community

Semantic UI also has a vibrant community and a variety of resources:

  • GitHub: A place to contribute to the project or report issues.
  • Gitter: A chat room for real-time discussions with other developers.
  • Theming Marketplace: A platform for sharing and selling custom themes.


Accessibility is an important aspect of web development, ensuring that all users, regardless of disability, can use and navigate your site.

Foundation Accessibility

Foundation places a strong emphasis on accessibility and includes features like ARIA attributes and keyboard-friendly navigation out of the box.

<!-- Example of an accessible menu in Foundation -->
<ul class="dropdown menu" data-dropdown-menu>
    <a href="#0">Item 1</a>
    <ul class="menu">
      <li><a href="#0">Item 1A</a></li>
      <!-- More items -->
  <!-- More items -->

Foundation’s components are designed to be accessible, and their documentation often includes best practices for maintaining accessibility.

Semantic UI Accessibility

Semantic UI also includes several accessibility features, such as roles and ARIA attributes. However, it’s important to ensure that custom implementations maintain these standards.

<!-- Example of an accessible button in Semantic UI -->
<button class="ui button" role="button" aria-pressed="false">Click Me</button>

Semantic UI’s readability-focused approach can contribute to better accessibility, but it’s still essential to test and verify accessibility compliance.


Both Foundation and Semantic UI are powerful and feature-rich CSS frameworks that can significantly speed up the front-end development process. Foundation is known for its mobile-first approach, flexibility, and emphasis on performance and customization. Semantic UI is recognized for its human-friendly HTML, comprehensive theming capabilities, and rich UI components.

When choosing between Foundation and Semantic UI, consider factors like your project requirements, the importance of performance, the need for customization, community support, and the emphasis on accessibility. Both frameworks have their strengths and are capable of powering the front-end of any modern website.

Ultimately, the decision will come down to personal preference and the specific needs of your project. It’s worth experimenting with both to see which one aligns better with your workflow and the goals of your website.

Remember to explore the official documentation and community resources to get the most out of whichever framework you choose:

By understanding the nuances of Foundation and Semantic UI, you’ll be well-equipped to make an informed decision and build a website that’s not only visually appealing but also robust, accessible, and user-friendly.

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