How to check Bootstrap version

To check version of the Bootstrap open /css/bootstrap.css file and on the top of this file, there is a version number.

You can also review version history by checking Releases log. 

        
            
          /*!
          * Bootstrap v5.0.0-beta3 (https://getbootstrap.com/)
          * Copyright 2011-2021 The Bootstrap Authors
          * Copyright 2011-2021 Twitter, Inc.
          * Licensed under MIT (https://github.com/twbs/bootstrap/blob/main/LICENSE)
          */