The most popular front-end framework for developing responsive, mobile first projects on the web.
Designed for everyone, everywhere.
Bootstrap makes front-end web development faster and easier. It’s made for folks of all skill levels, devices of all shapes, and projects of all sizes.
Preprocessors (Sass and Less support)
In addition to vanilla CSS, Bootstrap includes support for the two most popular CSS preprocessors, Less and Sass.
One framework, every device. (Responsive across devices)
Bootstrap easily and efficiently scales your project with one code base, from phones to tablets to desktops.
With Bootstrap, you get extensive and beautiful documentation with hundreds of live examples, code snippets, and more.
Built with Bootstrap.
Millions of amazing sites across the web are being built with Bootstrap. Get started on your own with our growing collection of examples or by exploring some of our favorites.
A brief history
In the earlier days of Twitter, engineers used almost any library they were familiar with to meet front-end requirements. Inconsistencies among the individual applications made it difficult to scale and maintain them. Bootstrap began as an answer to these challenges and quickly accelerated during Twitter’s first Hackweek. By the end of Hackweek, we had reached a stable version that engineers could use across the company.
With the help and feedback of many engineers, Bootstrap has grown significantly to encompass not only basic styles, but more elegant and durable front-end design patterns. This release represents our first public 1.0 release and the open sourcing of many months of hard work.
Why use Bootstrap
At its core, Bootstrap is just CSS, but it’s built with Less, a flexible pre-processor that offers much more power and flexibility than regular CSS. With Less, we gain a range of features like nested declarations, variables, mixins, operations, and color functions. Additionally, since Bootstrap is purely CSS when compiled via Less, we gain two important benefits:
When you take a closer look at Bootstrap, you will notice we have separated the development files into seven distinct files:
- reset.less A CSS reset originally made by Eric Meyer and modified for our use to remove unnecessary elements
- preboot.less Color variables and mixins for things like gradients, transparencies, and transitions to simplify vendox-prefixed CSS blocks to one line of code each
- scaffolding.less Basic and global styles for generating a grid system, structural layout, and page templates
- type.less Headings, body text, lists, code, and more for a versatile and durable typography system
- patterns.less Repeatable interface elements like navigation, modals, popovers, and tooltips to take you beyond the default scaffolding styles
- forms.less Durable styles for various input types, form layouts, and control states.
- tables.less Styles for tabular data in a number of varied displays
Since we opted to break our CSS into more manageable chunks for easy organization and iterations, compiling these files with Less means you end up with just one CSS file to include.
Why it works
Bootstrap works by providing a clean and uniform solution to the most common, everyday interface tasks developers come across. At Twitter, Bootstrap has quickly become one of our many go-to front-end tools when starting new applications and sites. This is because while it is very extensive, it’s flexible enough to work for many unique design needs.
Today, you can use Bootstrap to throw together quick prototypes or guide the execution of more sophisticated designs and larger engineering efforts. In other words, Bootstrap is a very simple way to promote quick, clean and highly usable applications.
We look forward to working with the open source community to evolve Bootstrap.
Where Bootstrap is heading
We want to keep working on slimming down Bootstrap’s already tiny footprint while also increasing the breadth of what it covers. As always, we’d love your feedback and hope you find it useful. If you’d like to help make Bootstrap better, feel free to fork it, file issues and watch its progress over on GitHub.