How long does it take Google to process 14 million 301 redirects? How about 360,000 redirects for Bing?
A year ago a publisher that we work with decided to discontinue a large domain and migrate only a small portion of its content to a new subdomain on a different, existing domain.
I realize that sounds a bit cryptic. I’m not at liberty to identify the domains involved, but I’ve found it interesting to follow the resulting indexation counts and wanted to share that in general terms.
The day of the migration Google had 14,100,000 URLs from the discontinued domain in its index, according to a [site:domain.com] search. Bing had only indexed 360,000 URLs (whaddup Bing?).
An interesting aspect of the migration is that only a small portion of the content was being republished on the new subdomain. Those pages got a 301 redirect to the corresponding new URL; everything else was given a 301 redirect to the new home page.
With so many URLs involved, and with a large number of 301 redirects all pointing to a single URL, I was curious how long it would take Google and Bing to process all the redirects.
A year has now passed and I can report back that, at least for Google, it is still a work in process.
Here is the timeline to-date:
|Google index count||Bing index count|
A few things to note:
We were not directly involved in this migration so I don’t have all the details on how it was managed in terms of the redirect mapping, XML sitemaps, updating links to the old URLs as possible, etc.
[site:] searches are considered a rough snapshot and the reported figures tend to fluctuate quite a bit. So you need to account for some oddities and inaccuracies when monitoring index counts over time. But I still found it interesting how Google’s reported index counts jumped around quite a bit, especially from 500K in late May back to 8 million in early June.
In looking through the remaining indexed pages in Google today I see that about 270 URLs are on a subdomain of the discontinued domain that is no longer maintained but is still active and accessible.
Nearly all the remaining URLs in Bing’s index are also on this still active subdomain. So based on that it looks like, except for some periodic fluctuations, Bing had mostly taken care of business (albeit it with a much smaller number of URLs) within a couple months.
As for the remaining 2K+ www pages in Google’s index, after jumping to page 20 of the [site:] results the reported figure drops to 192 along with an omitted results message:
So the migration process is largely completed but it can take quite a while to clean things up entirely.