Bootstrap 3 Vs Bootstrap 4 : What’s New?

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Bootstrap 3 Vs Bootstrap 4 : What’s New?

 As you would probably know, the Bootstrap framework has been the leading choice of millions of front-end developers for a very long time. This open-source framework enables website designers and front-end developers to easily create a highly-responsive and good-looking modern website.

Users who incorporate the use of this fascinating framework will be able to gain access to the basic structure of both CSS and HTML along with predefined classes. This will in turn help developers to considerably improve the responsiveness of their website. There are plenty of different versions of the Bootstrap framework available out there.

However, Bootstrap 3, which was launched in the year 2013 and Bootstrap 4 that was released in 2017 are the popular choices of users these days. If you are not familiar with the Bootstrap framework, then you might find it difficult to decide which one of them is the best choice for your project. This is why we have compiled a list of differences between Bootstrap 3 and Bootstrap 4 to help you make an informed decision.


Flexbox is one of the crucial features of the Bootstrap 4 framework, but it is unavailable with the Bootstrap 3 framework. This useful feature allows you to change the size of grid columns, manage the alignment of layouts, navigate components, and even change complex layout formation with ease.

On the other hand, Bootstrap 3 relied on floats to carry out the above-mentioned tasks. However, the innovative Flexible Box Layout makes it a lot simpler to create design flexible responsive layout structure even without using positioning or float.

In fact, designers and developers who use the Flexbox will be able to do the following tasks with the utmost ease.

  • Create equal width grid columns
  • Design cards with equal width and height
  • Develop utility classes to easily alter direction, scaling, alignment, display, and more.
  • Add auto margin for easy spacing
  • Create justified navigation and button groups

Improved Grid System

Bootstrap 4 Grid System

The Bootstrap 3 framework contained four unique grid classes and they were named as col-xs-3, col-sm-3, col-md-3, and col-lg-3. The latest version of the open-source framework, Bootstrap 4 is equipped with five separated grid classes and they are .col-, .col-sm-3, .col-md-3, .col-lg-3, and .col-xl-3. An important thing to remember is that Bootstrap 4 has eliminated xs from the lowest breakpoint.

The new class is actually added for the sole purpose of including a new breakpoint, which will in turn offer better support to small devices with screen sizes under 576 px. This means that your website will look good on even devices with such small screen sizes, which is due to the addition of the latest xs class.


The Bootstrap Navbar in the latest version of the framework is written entirely in the flexbox. The Bootstrap Navbar incorporate the use of flexbox utilities to improve layout customization and responsiveness. Some of the important changes in the Bootstrap 4 Navbar are the following.

  • The use of the .nav base class has been stopped, which means that only the .navbar-nav class will be required for future projects.
  • The responsive navbar toggle has been updated from .navbar-toggler to  .navbar-toggler-icon for improved customization.
  • The old  .navbar-toggle class is the .navbar-toggler in the latest version of the framework.
  • Multiple numbers of excellent preset color options are available with the Bootstrap 4 Navbar.
  • Users can use the class .form-inline instead of the .navbar-form class because the latter one is no longer required.

Sass Instead of Less

Sass logo

The CSS source file update from LESS to SASS is another major difference between the Bootstrap 3 and Bootstrap 4 framework. SASS is undoubtedly a lot more powerful when compared to LESS, and it even has handy functionalities like extend, nested media queries, rem, em, mixing, loops, logical operators, and more.

It is true that LESS is a lot simpler to learn, which means that users who are new to the world of web designing and open-source frameworks will need a few weeks or more to get comfortable with SASS. It is crucial to note that there are plenty of options available for compiling SASS to CSS too.

Relative CSS units.

The most popular and best practice of typography on the web is to incorporate the use of relative units of px, em, and rem. It might come as a surprise to many readers when they hear the fact that the Bootstrap 4 framework uses rem instead of px, as the former is a lot more flexible when compared to the latter.

Designers and developers who use rem will be able to easily scale elements up and down without the worry of getting stuck with a certain fixed size. This will, in turn, help you to easily adjust the design of your website and make it a lot more responsive. However, the Bootstrap 4 framework still uses pixels for container widths, grid breakpoints, and media queries because viewports will not get affected by the type size.

Cards Instead of Wells, panels, and Thumbnails

Card group

The Bootstrap 4 framework has replaced the thumbnails, panels, and wells with cards. Cards serve the exact same function thumbnails, but they are a lot more flexible and capable of supporting different types of content. As a result, users will not be able to find .well, .panel and .thumbnail classes, instead, they will find card, .card-block and some other modifier classes.

An important point to remember is that cards are also built with flexbox, which means that users will be easily able to align them. In fact, developers and designers who use the Bootstrap 4 framework will be able to create cards of the exact same height with the help of a card-group. Cards are graphically catchy, informative, and highly-useful when it comes to categorizing information.

Drops IE8 and IE9 Support

You might be probably aware that the Bootstrap 3 framework offered support for both IE9 and IE8. However, website designers and developers will be surprised to hear the fact that the latest version of the Bootstrap framework has dropped IE8 and IE9 support.

The good news is that the Bootstrap 4 framework offer support for just iOS 7+ and IE9+, which means that the support for the earlier versions has also been dropped. So, if you wish to keep using any of these browsers, then it is best to continue with the Bootstrap 3 framework.

Tooltips and Popovers

The Bootstrap 4 framework incorporates the use of a powerful third-party library, which is called as the tether. This excellent third-party library is used for the sole purpose of positioning components on relation to one another on web pages. If you are looking for a tool that will ensure improved auto-placement of tooltips and popovers, then you do not need to luck further because tether is the best choice for you.

In simple words, tether can be defined as a third-party JavaScript library used by thousands of website designers and developers from all over the globe. The tether should be included in the HTML file by using a <script> tag right before adding your bootstrap.js file.

Variable Customization

Almost all the variables that are used in the Bootstrap 4 framework is usually included in a file, which is named as _variable.scss. Users will be easily able to copy the variables into another file, which is called as _custom.scss in order to change the value of the variables or to simply remove the default tag. In this case, users will have to update only a single variable during the process of customization.

Utility Classes

If you are a person who has used the Bootstrap framework for his/her projects, then you would be probably aware that this framework contains specific classes called as utility classes. These utility classes enable users to easily and quickly arrange components within the layout. A number of changes have been made to the utility classes of Bootstrap 4, and even a few new utility classes have also been added to the framework.

The best thing about utility classes is that they are capable of considerably improving the development time of a project. For instance, users will be able to add padding values or a responsive-friendly margin to one of the elements by using spacing utilities. Flexbox utilities allow users to easily manage alignment, sizing, and layout while display property utilities assist users by allowing them to block or change the alignment of elements.


From the above statements, it is evident that the latest version of the Bootstrap framework has a number of improvements and changes in styles, typography, layouts, and more. If you wish to learn more about the new updates and changes in the Bootstrap 4 framework, then it is best to pay a visit to the official website of Bootstrap.

The newly launched and updated tools and features in this open-source framework will surely help you to design flawless websites. Users who have not yet used this framework and the ones who wish to learn more on how to select a bootstrap admin template should consider getting in touch with our expert team of developers and designers.



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