20 Best Free CSS Frameworks 2021

Compare and find your new choice of free responsive CSS frameworks that are lightweight and feature-rich with styled UI components. The advantages of using a CSS framework in your project outweigh the disadvantages. Some of the advantages are clean code, grid design, pre-built UI components, easy for your team to manage, ease of accessibility features, and documentation. In short, you get your project done in less time with fewer workforce.

Lightweight frameworks are favored by many experienced developers as they give a jumpstart to designing a website or mobile app. Large CSS frameworks like Bootstrap and Foundation might be hard to manage for larger projects. But with the help of LESS and SASS preprocessors, we get the option to modify the CSS output for better performance.

I have chosen to include only responsive frameworks which will scale easily on multiple mobile, tablet, desktop devices. Share in your comments and let us know if we missed any important frameworks here.

Mobile responsive designs are the need of the hour. Every website is required to be responsive so that users can easily view the websites on a variety of devices and screens. All frameworks are made with mobile-first approach strategy. Let us take a look at these responsive CSS frameworks that can help you develop websites which look perfect on all screens.

Bootstrap Bulma Materialize Pure CSS Tailwind CSS MDB Spectre Foundation UIkit Semantic UI Tachyons Milligram Chota
Mobile Menu
Pure CSS
Grid Layout
SVG Icons
Release 2011 2016 2016 2019 2016 2011 2017 2014 2015 2015 2017
Updated 2021 2021 2018 2021 2021 2021 2020 2020 2021 2018 2018 2020 2020

What is a CSS framework ?

Frameworks have been used for years now to build websites since they essentially remove most of the groundwork. This gives you the ability to concentrate on designing the website without having to start from scratch. With the help of a framework, you can save time by not having to repeat common code. CSS frameworks come with a set of rules and mixins that help you utilize responsive grids and spacing for your website.

What is CSS reset and why is it important?

There was a time when styles did not have a form of standardization. In web design, browsers have helped us bridge most of the styling issues. Browsers apply their own default parameters if you choose not to define the parameters in your style sheet. This sometimes ends up giving your website a different look depending on the browser your users may be using.

This is where a CSS reset file comes in. With the help of CSS Reset, you can reset all these browser styles to zero. This means that visitors will not see any styles on your website which you did not apply to your style sheet.

Which framework is best for web development?

Frameworks come in a variety of shapes and sizes. Web designers sometimes choose heavy frameworks which offer more web styles and at times they use frameworks that are lightweight. Remember that choosing a heavy framework may make work easy for you, but the footprint or page speed might be affected if you don’t customize it well.

On the other hand, if you use a lighter framework, the chances of adding your own creativity and coding effort are higher. It however gives you the chance to customize your website according to your vision instead of dictating the style of the website.

As a designer, you may end up working with both types of frameworks, but when it comes to choosing between the two, a good CSS framework will always allow you to integrate the functionality of the framework with your visualization of the website without bloating the website with its own designs.

Bootstrap and Foundation has a large footprint but they let you customize according to your website requirements reducing the overall footprint of CSS and JS files.

The best CSS framework is one that is lightweight and allows a wide range of customization to give your website a design that meets your vision rather than something that is dictated by the framework.

Responsive CSS Frameworks

Bootstrap 5 Framework (Official website)

CSS Minified: 152KB CSS gzipped: 22.4KB

JS Minified: 78KB JS gzipped: 21.8KB

This is the most popular CSS framework that has been fine tuned to make mobile responsive websites over the last decade. The mobile-first approach makes it easier to build websites that modern-day businesses need. Every web developer at some point will atleast try Bootstrap. Many job prospects require frontend developers to have some knowledge of Bootstrap or grid based frameworks.


  • Pre-built components
  • SASS for custom CSS
  • Supports extra small devices
  • Grid layouts & flexbox
  • Easy to use


  • Bulky in size
  • Websites look the same

Bulma (Official website)

CSS Minified: 200KB CSS gzipped: 27.2KB

Bulma is getting popular recently with its pure CSS approach. It also comes with a extensive library of JavaScript components for accordions, modal and so on. However the file size of minified CSS version is slighter heavier than Bootstrap 5.


  • Pure CSS
  • SASS for custom CSS
  • Lots of UI components
  • Grid & Flexbox
  • Great community
  • Updated


  • Modal doesn’t work without JS
  • Bulky size
  • No small breakpoints

Materialize (Official website)

CSS Minified: 139KB CSS gzipped: 20.9KB

JS Minified: 177KB JS gzipped: 41.6KB

Materialize uses material design created by Google for its core CSS styles. The grid layout of this framework is similar to other CSS frameworks, however, it differs in UI design with its shadows and material UI colors.


  • SASS for custom CSS
  • Lots of JavaScript components
  • Sleek design
  • Clean classes
  • Easy to copy snippets


  • Not updated for sometime
  • No Flexbox

Pure CSS (Official website)

CSS Minified: 18KB CSS gzipped: 2.8KB

This is a lightweight CSS framework and used by many developers for quick website projects. All modules are responsive and every CSS line carefully thought-out.


  • Only 2.8KB
  • Clean code
  • Grid Layout
  • No JavaScript


  • No SASS
  • Very basic use

Tailwind CSS

Its greatest advantage is the beginner friendly use of classes and its smart coding. This framework outputs the CSS stylesheet with the classes you use in your HTML code, which is awesome for high performance websites. You need nodeJS to make this work for your project unlike other CSS frameworks, this option is a deal breaker for many.


  • Smartly coded with JS
  • Clean modular code
  • Grid & Flexbox Layout


  • Too many classes
  • Boring HTML
  • The free version is useless
  • Need nodeJS to work

Semantic UI Framework

Semantic User Interface

Semantic empowers designers and developers by creating a language for sharing UI. Lose the Hieroglyphics: Semantic is structured around natural language conventions to make development more intuitive. Have a conversation with your components: Semantic gives you a variety of UI components with real-time debug output, letting your code tell you what its doing.

Examples Download

Foundation Framework

foundation css framework

Foundation 5 is built with Sass, a powerful CSS preprocessor, which allows us to much more quickly develop Foundation itself and gives you new tools to quickly customize and build on top of Foundation.

Examples Download

UIkit Framework

ui kit

UIkit gives you a comprehensive collection of HTML, CSS, and JS components. It can be extended with themes and is easy to customize to create your own look.

Examples Download


Let us know which one you find useful and if we missed a feature to compare. We are on a look for new CSS frameworks that make an impact on website design and the mobile app development process.

1 thought on “20 Best Free CSS Frameworks 2021”

  1. It’s amazing/depressing how many of these (particularly as you go down the list) haven’t been kept up; the field seems to have been left to Bootstrap, Material UI, and Foundation, with Semantic UI folks hoping for new life in the project.

    What I’m looking for is a Semantic UI-like collection of components that work nicely within a STANDARD CSS Grid. Everybody seems to have implemented their own, and nobody implements grid areas, which is something we desperately need. Not a happy camper at this point.


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