Contributing to Bootstrap

Looking to contribute something to Bootstrap? Here’s how you can help.

Please take a moment to review this document in order to make the contribution process easy and effective for everyone involved.

Following these guidelines helps to communicate that you respect the time of the developers managing and developing this open source project. In return, they should reciprocate that respect in addressing your issue or assessing patches and features.

Using the issue tracker

The issue tracker is the preferred channel for bug reports, features requests and submitting pull requests, but please respect the following restrictions:

  • Please do not use the issue tracker for personal support requests. Stack Overflow (twitter-bootstrap-3 tag) or IRC are better places to get help.

  • Please do not derail or troll issues. Keep the discussion on topic and respect the opinions of others.

  • Please do not open issues or pull requests regarding the code in Normalize (open them in their respective repositories).

Bug reports

A bug is a demonstrable problem that is caused by the code in the repository. Good bug reports are extremely helpful, so thanks!

Guidelines for bug reports:

  1. Use the GitHub issue search — check if the issue has already been reported.

  2. Check if the issue has been fixed — try to reproduce it using the latest master or development branch in the repository.

  3. Isolate the problem — ideally create a reduced test case and a live example. This JS Bin is a helpful template.

A good bug report shouldn’t leave others needing to chase you up for more information. Please try to be as detailed as possible in your report. What is your environment? What steps will reproduce the issue? What browser(s) and OS experience the problem? Do other browsers show the bug differently? What would you expect to be the outcome? All these details will help people to fix any potential bugs.


Short and descriptive example bug report title

A summary of the issue and the browser/OS environment in which it occurs. If suitable, include the steps required to reproduce the bug.

  1. This is the first step
  2. This is the second step
  3. Further steps, etc.

<url> - a link to the reduced test case

Any other information you want to share that is relevant to the issue being reported. This might include the lines of code that you have identified as causing the bug, and potential solutions (and your opinions on their merits).

Feature requests

Feature requests are welcome. But take a moment to find out whether your idea fits with the scope and aims of the project. It’s up to you to make a strong case to convince the project’s developers of the merits of this feature. Please provide as much detail and context as possible.

Pull requests

Good pull requests—patches, improvements, new features—are a fantastic help. They should remain focused in scope and avoid containing unrelated commits.

Please ask first before embarking on any significant pull request (e.g. implementing features, refactoring code, porting to a different language), otherwise you risk spending a lot of time working on something that the project’s developers might not want to merge into the project.

Please adhere to the coding guidelines used throughout the project (indentation, accurate comments, etc.) and any other requirements (such as test coverage).

Adhering to the following process is the best way to get your work included in the project:

  1. Fork the project, clone your fork, and configure the remotes:


    Clone your fork of the repo into the current directory

    git clone

    Navigate to the newly cloned directory

    cd bootstrap

    Assign the original repo to a remote called “upstream”

    git remote add upstream “`

  2. If you cloned a while ago, get the latest changes from upstream:

    bash git checkout master git pull upstream master

  3. Create a new topic branch (off the main project development branch) to contain your feature, change, or fix:

    bash git checkout -b <topic-branch-name>

  4. Commit your changes in logical chunks. Please adhere to these git commit message guidelines or your code is unlikely be merged into the main project. Use Git’s interactive rebase feature to tidy up your commits before making them public.

  5. Locally merge (or rebase) the upstream development branch into your topic branch:

    bash git pull [--rebase] upstream master

  6. Push your topic branch up to your fork:

    bash git push origin <topic-branch-name>

  7. Open a Pull Request with a clear title and description against the master branch.

IMPORTANT: By submitting a patch, you agree to allow the project owners to license your work under the terms of the MIT License.

Code guidelines


  • Two spaces for indentation, never tabs.
  • Double quotes only, never single quotes.
  • Always use proper indentation.
  • Use tags and elements appropriate for an HTML5 doctype (e.g., self-closing tags).
  • Use CDNs and HTTPS for third-party JS when possible. We don’t use protocol-relative URLs in this case because they break when viewing the page locally via file://.
  • Use WAI-ARIA attributes in documentation examples to promote accessibility.


  • CSS changes must be done in .less files first, never just in the compiled .css files.
  • Adhere to the CSS property order.
  • Multiple-line approach (one property and value per line).
  • Always a space after a property’s colon (e.g., display: block; and not display:block;).
  • End all lines with a semi-colon.
  • For multiple, comma-separated selectors, place each selector on its own line.
  • Attribute selectors, like input[type="text"] should always wrap the attribute’s value in double quotes, for consistency and safety (see this blog post on unquoted attribute values that can lead to XSS attacks).
  • Attribute selectors should only be used where absolutely necessary (e.g., form controls) and should be avoided on custom components for performance and explicitness.
  • Series of classes for a component should include a base class (e.g., .component) and use the base class as a prefix for modifier and sub-components (e.g., .component-lg).
  • Avoid inheritance and over nesting—use single, explicit classes whenever possible.
  • When feasible, default color palettes should comply with WCAG color contrast guidelines.
  • Except in rare cases, don’t remove default :focus styles (via e.g. outline: none;) without providing alternative styles. See this A11Y Project post for more details.


  • No semicolons (in client-side JS)
  • 2 spaces (no tabs)
  • strict mode
  • “Attractive”

Checking coding style

Run grunt test before committing to ensure your changes follow our coding standards.


By contributing your code, you agree to license your contribution under the MIT license.

Prior to v3.1.0, Bootstrap was released under the Apache License v2.0.