We actually covered this topic before when we covered how Gary Illyes of Google spoke about being on the edge of quality several months ago. John Mueller of Google is now talking about being on the "edge of indexing" and how that shows some of your pages have quality issues.
If you see that some of your pages are showing up in the index and dropping out and then coming back, which we reported as a possible bug before, it might not be a bug but a feature.
Google said this can be because your pages are on the threshold of having enough quality to be in the Google index and not enough quality to be in the Google index.
John Mueller of Google reiterated that on Twitter yesterday when he said "if you're teetering on the edge of indexing, there's always fluctuation." "It basically means you need to convince Google that it's worthwhile to index more," John added.
In short, if you see your pages jumping in and out of the index, you probably have some quality issues with those pages.
Here is more context on the tweets:
There's nothing really special or new about "discovered / not indexed" -- it's mostly just that this was previously (before it got added to SC) not something you saw. It's essentially "we saw you, but maybe later, or never". Does it confuse people too much? Should we remove it?
— 🧀 John 🧀 (@JohnMu) November 8, 2021
Yeah, that can happen. But it can also happen that it drops out again a week later, or a different URL drops out. If you're teetering on the edge of indexing, there's always fluctuation. It basically means you need to convince Google that it's worthwhile to index more.
— 🧀 John 🧀 (@JohnMu) November 8, 2021
And how to you give Google more quality? John says through awesomeness:
Awesomeness.
— 🧀 John 🧀 (@JohnMu) November 8, 2021
Lots of awesomeness.
All kinds of awesomeness.
And add more awesomeness.
Since we don't have an understanding of the URL (it's not indexed), we have to pull in the rest of the site to better understand its potential context within the site, and within the rest of the web. Is it something the web has been waiting for? Or is it just another red widget?
— 🧀 John 🧀 (@JohnMu) November 8, 2021
Like I said above, this was covered before, and if you want to improve your site's indexing ratio, you need to improve quality. Google has been saying they do not index everything for years, Google simply won't index all your pages and it is impossible for Google to index everything, Google said.
Forum discussion at Twitter.
