Google's John Mueller said the URLs listed in the "referring page" section of the URL Inspection Tool is not really important. It is just a technical thing showing which URL(s) Google first discovered the page. It has not quality indication and not something to be concerned with, according to John.
The referring page is found in the URL Inspection Tool in Google Search Console, under the "Coverage" section. Early last year, Google added multiple referring URLs to that report. In any event, here is a screenshot of that story and how Google found that page first - yes, through URL shortener URLs that probably pass almost no signals.
John said at the 30:35 mark in the video "the referring page in the Inspection Tool is kind of where we first saw the mention of your pages." He added "It's not a sign that you need to kind of like make sure that it was first found on some very important part of your website."
Here is the video embed where he said this:
Transcript:
When using URL inspection tool in Search Console on established highly visible pages, how concerning is it that the referring pages listed are long retired microsite domains?
That would not bother me at all. So in particular the referring page in the Inspection Tool is kind of where we first saw the mention of your pages. And if we first saw them on some random website then that's just where we saw them and that's kind of what we list there. It doesn't mean that there's anything bad with those pages.
So from our point of view that's purely a technical thing, it's like well here's where we found it. It's not a sign that you need to kind of like make sure that it was first found on some very important part of your website. So if your pages are indexed I think that's the important part there. I wouldn't really worry about where they were first found.
More: However, it is smart to check the referring pages to make sure you aren't doing something wrong on your own site (like w/weird url parameters). But again, it's just where Google first found the urls. They aren't a sign of anything terrible SEO-wise: https://t.co/6cZolgJQ31 pic.twitter.com/azCAWJ9uCg
— Glenn Gabe (@glenngabe) February 19, 2022
There is some continued discussion on the Twitter thread from Glenn about this, if you are interested.
Forum discussion at Twitter.
