How to check what Bootstrap version a website is using?

Updated Written By Christoffer
How to check what Bootstrap version a website is using?

If you want to check which Bootstrap CSS version is being used on a website, you have two options: 1) use an online tool or 2) check for the version manually.

Method 1) Use an online Bootstrap version checker

This is the simplest way to check the Bootstrap version:

  1. Copy the website URL you want to check.
  2. Use our free Bootstrap version detector tool.
  3. In the results table, you can see a Bootstrap row. The actual version used on the searched website is in parentheses.

Method 2) Check the files manually

If you’re more technical, you can check the source files manually. Though this is a manual job, you can, in simple steps, do it yourself.

  1. View Source Code: Right-click on the web page and select “View Page Source” or a similar option, depending on your browser. This will open a new tab showing the page’s HTML source code.
  2. Search for Bootstrap Reference: Press Ctrl + F (or Cmd + F on Mac) to open the search box in your browser. Type “bootstrap” to search for any links or references to Bootstrap files in the code. You’re looking for lines that link to Bootstrap’s CSS or JavaScript files.
  3. Check the File Paths or Names: Look for the Bootstrap file paths or names in the search results. They often include the version number. For example, a link to a Bootstrap CSS file might look like this: <link href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" rel="stylesheet">.
  4. Use Browser Developer Tools: Alternatively, you can use your browser’s Developer Tools to inspect the network requests or search within the source files loaded by the page. To do this:
    • Open Developer Tools (usually F12 or Ctrl + Shift + I / Cmd + Opt + I on Mac).
    • Go to the “Network” tab and reload the page to capture all the network requests.
    • Filter or search for “bootstrap” in the network requests and look for the CSS or JavaScript files linked to Bootstrap.
  5. Inspect the JavaScript Console: Some versions of Bootstrap add information about the version to the JavaScript object. You can go to the “Console” tab and type in the browser’s Developer Tools and type $.fn.tooltip.Constructor.VERSION (for Bootstrap 3) or bootstrap.Tooltip.VERSION (for Bootstrap 5) to see if the version is logged to the console. Note that this method might not work for all versions.

If the website is minifying or bundling its assets or using a custom build of Bootstrap, it might be harder to identify the version. In such cases, looking for specific features or classes unique to certain Bootstrap versions might give you a hint.

What is Bootstrap CSS?

Bootstrap CSS is a popular, open-source framework for designing websites and web applications. It’s mainly known for its responsive grid system, pre-built components, and powerful JavaScript plugins.

The main idea behind Bootstrap is to enable developers to create modern, responsive, and attractive web pages with minimal effort.

Article by

Christoffer Pettersen

Founder, Web developer

Pettersen is the founder of Stackcrawler, a platform that helps analyze tech stacks. He is passionate about new trends and technologies in the software industry.