Stack Overflow’s CSS and Design Pattern Library. Stacks is an atomic CSS library with classes and components for rapidly building Stack Overflow.

Downloads in past


501761.3.616 days ago5 years agoMinified + gzip package size for @stackoverflow/stacks in KB


Stacks is Stack Overflow’s design system. It includes the resources needed to create consistent, predictable interfaces and workflows that conform to Stack Overflow’s principles, design language, and best practices. Our documentation is built with Stacks itself, using its immutable, atomic classes and components. The Stacks website documents:


  • Semantic and accessible component markup
  • Cross-browser compatible Less / CSS


  • Email templates & components
Stacks documentation can be found at https://stackoverflow.design/

Table of contents

Using Stacks

Using Stacks is outlined in our usage guidelines.

Building Stacks

To contribute to Stacks documentation or its CSS library, you’ll need to build Stacks locally. View our building guidelines. Having trouble getting these steps to work? Open an issue with a setup label.

Testing Stacks

Stacks has implemented visual regression testing with Backstop. To test if your new feature introduces visual regressions, run npm run test in a new Terminal window while Stacks is running. After the tests have run, a new browser window with any regressions will show. If the regressions are desired, you can run npm run approve to establish the new baseline. Individual routes to test are found in backstop.json

Bugs and feature requests

Have a bug or feature request? First search existing or closed issues to make sure the issue hasn’t been noted yet. If not, review our issue guidelines for submitting a bug report or feature request.


If you’d like to contribute to Stacks, please read through our contribution guidelines. Included are directions for opening issues, coding standards, and notes on development.


Code and documentation copyright 2017-2022 Stack Exchange, Inc and released under the MIT License.