So, what you need to do is add ‘/wp-admin/’ at the end of the domain (homepage URL) of the website. If it redirects to the login page, then you can determine that the website uses WordPress.

Adding wp-admin to Domain

For example, if your website URL is ‘https://example.com‘, then add ‘/wp-admin/’ at the end of it. After that, open ‘http://example.com/wp-admin/’.

Now, if it shows a login page like the below screenshot, then it means that the site uses WordPress.