DNS over HTTPS is a Firefox add-on designed to enhance users' online privacy by providing critical information about websites. This tool retrieves the Fully Qualified Domain Name (FQDN), domain name, and IP address when users visit a website, ensuring that users are aware of the site's identity. Additionally, it connects to a DNS over HTTPS (DoH) server to fetch the site's IP, Pointer (PTR), and Canonical Name (CNAME) records, allowing for comprehensive data comparison.

The add-on features a color-coded system to indicate the privacy status of the website being accessed. A green icon signifies normal conditions, while a yellow icon indicates a private IP. A red icon alerts users that the IP addresses obtained from the browser and DoH server differ, and the domain name does not appear in the PTR/CNAME records, highlighting potential security concerns. This functionality makes DNS over HTTPS a valuable tool for maintaining web security.