In case you’re wondering, setting a page to noindex is just a way of telling the search engines (Google, mostly) that you don’t want that page (or URL) to be displayed in the search results.
Why would someone want to noindex a page? Well, people may noindex a page for various reasons, but usually, it may be because they feel the page is low-quality, thin, or doesn’t provide much value.
That was actually the concern behind a question that was asked on Google’s most recently-released webmaster Q&A session, English Google SEO office-hours from August 20, 2021.
At the ~10:41 mark, a participant gave Google’s John Mueller some information about his situation.
Basically, this participant (a webmaster, basically), has an option for people to register for his site, and when they do, they get user profile pages. But, these user profile pages–at least, a good portion of them–tend to be thin pages.
(By the way, just because they’re thin, low-content pages does not mean they’re necessarily low quality. I explained that here.)
Anyway, this participant has ended up noindexing many of these.
The participant went on to ask, “But, by doing that, am I losing the value of backlinks that are pointing to those pages and to the site as a whole?”
To which, John Mueller replied, “Maybe, maybe…” He went on to list a few reasons why, detailing a bit of the mechanics that go on.
The Value of Links
This is probably something you know, but it’s always good to hear someone from Google asserting it. In this case, good, high-quality links pointing to your site are valuable.
Of course, the webmaster posing the question knows this.
So, as I understand Mueller, if a page is set to noindex, Google may have that page in it’s internal record, but not show it on a search results page.
According to Mueller, if that status persisted “…we won’t need to keep it in our index. And, in those cases, essentially, those links pointing to the noindex page, they…they go nowhere, and…then we drop them.”
So, “If it’s critical to your website that you use…kind of…these noindex pages to forward signals or PageRank or what have you, within your website, then I would see if there’s a way to make them indexable.”
One thing Mueller said was that perhaps there’s a way for the webmaster to figure out which of the profile pages are higher-quality, and keep those indexed, and conversely, figure out which of the profile pages are lower-quality, and have those be noindexed.
There you have it. So, you have a decision to make: either noindex them and lose the value of incoming links, or index them, and retain the value of the links coming to your site.