Catastrophic site-wide de-ranking without cause

85% of our posts just dropped out of the top 100 results over a night

[simste]

Hi,

On November 9th, we stumbled across an unknown issue with our website. 85% of our blog posts (around 150) just dropped out of the top 100 results over a night. While before, a lot of them were ranked in the top 20 results.

Background:

1. Our main website runs on this URL: <snip>
   
2. Our blog runs on a subdomain: blog.example.com (we moved our blog from a subfolder (example.com/blog/) to a subdomain on October 17th, 2022). It used to run on gatsby.js and now runs on WordPress.
   
3. During the migration, we ensured that all of our URLs were properly mapped with 301 redirects and had no downtime.
   
4. The new blog (subdomain) ranked perfectly fine until November 9th. Also, example.com was not impacted, so it seems that the issue relies on our blog.
   

To conclude, our team checked everything that we could think of. This includes robots.txt, meta robots tags, redirects, sitemaps, hreflangs, canonicals, server logs, GSC errors (no manual action notices), backlinks, content, internal and external links response codes, and more. Still, we could not find what happened on November 9th.

Does anyone have any other ideas about what could have happened?

[edited by: engine at 3:53 pm (utc) on Nov 15, 2022]
[edit reason] Please see WebmasterWorld TOS and this forum Charter [/edit]

[IamnotMattCutts]

Google treats a subdomain as a seperate website with some association. So you've moved all your blog content from a URL that I assume had some authority to one that has none on October the 17th. And then a drop out on the 9th of Nov. It will take time for those rediretcs to kick in, and even then will it have it's same traction in search? I'm not sure.

[RedBar]

Welcome to WebmasterWorld simste

Sorry to hear of your problem however:

During the migration, we ensured that all of our URLs were properly mapped with 301 redirects and had no downtime.

You are 100% sure your 301s are correct?
Were they ALL working correctly before 9th Nov and were they tested?
Was this your own htaccess file or WPs?
I have actually experienced several times a faulty htaccess file and never, ever found out why it was faulty yet it took an entire site offline.

[beaverman]

Hello.

On 4-5th November, there was one of the latest unconfirmed Google updates, possibly connected to their October Spam Update (19-21st October). A few were hit, based on the comments on Seroundtable and BHW, while a few recovered.

[seroundtable.com...]

The dates don't match, though it is not unusual to see an effect somewhat later. Also, if you have your ranking factors recalculated for those articles when moving a key section to a subdomain, you may be more prone to update drops. Moreover, subdomains are treated like separate sites distinct from the main domain/site by Google when assessing trust: [searchenginejournal.com...]

So maybe just give it time, if you don't see SEO or technical issues?

[RedBar]

85% of our blog posts (around 150) just dropped out of the top 100 results over a night.

Are they stll indexed or completely disappeared?

Google treats a subdomain as a seperate website with some association.

Good point but 85% and not 100% just like that?

[simste]

You are 100% sure your 301s are correct?
Were they ALL working correctly before 9th Nov and were they tested?
Was this your own htaccess file or WPs?

1. I am sure the redirects are correct
2. Yes, they were, and I've tested them then and now
3. The redirects were made by our developers. I am not sure what exact method they used. However, it was definitely not through WordPress.

Google treats a subdomain as a seperate website with some association. So you've moved all your blog content from a URL that I assume had some authority to one that has none on October the 17th. And then a drop out on the 9th of Nov. It will take time for those rediretcs to kick in, and even then will it have it's same traction in search? I'm not sure.

I was definitely expecting changes in our search performance. However, I did not expect that 85% of our blog posts would go absolutely out of the top100 results, which seems weird.

[simste]

Are they stll indexed or completely disappeared?

They are still indexed, however, they do not show up for their target keywords (not in top100). While before November 9th, they used to show up.

[RedBar]

They are still indexed

That's good and supports IamnotMattCutts point with the sub-domain being treated as a new site.

An interesting test would be to reinstate a couple of the urls under their original example.com/blog/urls and see what happens ... but that's probably only me!

If it is being treated as a new site then good luck, for nearly all this year new sites have struggled unless they had totally unique content.

[tangor]

The OP's...

Catastrophic site-wide de-ranking without cause

...is inaccurate. There is cause:

Google.

And they will never tell you what changed, or why---not in any kind of fullness that one can address to solve "whatever it was" G targeted.

Just the nature of the game.

And since the web continues to grow at crazy rates of urls by the second somewhere along the way the serps will be made incomprehensible if all are allowed through.

I don't have an answer. But I DO KNOW the urls are indexed and I DO get traffic, just not as much as I used to. Attrition in mass and other absurdities of numbers a scale.

[simste]

An interesting test would be to reinstate a couple of the urls under their original example.com/blog/urls and see what happens ... but that's probably only me!

Yeah, that would be interesting, however, given our development situation, it might take too long to bring the old URLs back just for a test. Anyway, thanks for the insights!

[engine]

it might take too long to bring the old URLs back just for a test

I think testing that situation would help prove one way or the other, and i'd probably want to test that, too.

[jpalmer]

Late to the post here, but as others in this thread have already pointed out, G will treat blog.example.com as a separate domain.

Make sure your sitemap.xml is up to date, and then resubmit it via Search Console. While you're at it, resubmit to Bing Webmaster tools as well.

Might give G the kick in the pants needed to reevaluate the pages, and you may get some new traffic love from Bing!

Alternatively, pick your top 10 posts/pages that have disappeared, and do a Search Console URL inspection.

(But note: I am having serious trouble with my Search Console reporting files - 400+ of them, that aren't pages as being "Duplicates without cononical", and pages that are indexed and appearing in a site: url search, in Search Console being reported as "Page cannot be indexed: Not found (404)".

This has been going on since at least Noveber 2021. And this is when my search traffic from G started its slow decline. Like you, I've pulled my hair out checking and double checking all the possible causes, to no avail.

So either something is seriously wrong in Search Console or us chickens are plucked.)

Best of luck. Feel for you.

[simste]

Thanks for the insights, jpalmer. I did everything you mentioned and haven't found any issues. I start to believe that it was due to migration to the subdomain.

I'll be recovering some posts on old URLs. It'll be interesting to see if they come back to their previous rankings.

[beaverman]

@simste that's most surely the issue. Recently John Mu of Google explicitly said that it's not a good idea to host a content blog on a subdomain as it will not have the trust of the primary domain. E.g. it's more for some apps and such.

Can't find that news piece now.

[simste]

@beaverman That's a possible option, I will share the results of our test here