Most organizations use Google Analytics to track website visitors and for more statistics. Generally, they have the same Google Analytics ID across all subdomains of a root domain. This means we can perform a reverse search and find all the subdomains having the same ID. Hence, it helps us in the enumeration process.
Most people might be familiar with a browser extension called BuiltWidth. But using this extension or its website is a manual process. We need some sort of command-line utility. That's when AnalyticsRelationships comes to the rescue.
AnalyticsRelationships is a tool to enumerate subdomains via Google Analytics ID. It does not require any login and has the capability to bypass the BuiltWidth & HackerTarget captchas. This tool is available in 2 languages Python & Go. But the Go one is faster compared to the python one.