There are a few ways to tell if a site is Joomla-based. The first is to look for the “Joomla” logo in the footer of the website. If the logo is present, the site is likely a Joomla site. Additionally, many Joomla-based sites use the Joomla CMS as their primary content management system (CMS).
-The use of a ‘Joomla’ or ‘Joomla! Powered’ badge or logo
-The presence of a ‘What is Joomla?’ page or link
-The use of the Joomla! name or logo in the site’s domain name
-The inclusion of Joomla! core components, such as the content management system (CMS) or e-commerce solution
-The use of Joomla! templates or themes
-The use of Joomla! extensions
This means that the site’s content is likely organized in a Joomla-specific way and that the site’s administration interface, or “backend,” is likely based on Joomla. Finally, many Joomla-based sites include features that are specific to Joomla, such as the ability to create custom menus and articles, or to create custom forms.