There are 4 different ways to tell if a website or page is using Elementor.
1 – Elementor is visible on the left sidebar on the WordPress Dashboard.
2 – Elementor isn’t listed in the plugins. Plugins are listed in alphabetical order.
Dashboard > Plugins > Installed Plugins
3 – Elementor is listed in on the top tool bar.
4 – Elementor is listed as edit option for an individual page. Dashboard > Pages > All Pages