Google has published a new video about site migrations. John Mueller provided insights into how Google handles website migrations and how long they can take. The main points are that site migrations can be difficult and that a comprehensive plan must be in place before migrating.
The video begins with a question:
“We are currently going through a site migration and would also like to restructure the URLs on the site. Does this have any risks?”
Migrating a site usually means changing the domain name, sometimes due to a company merging with another or because of a rebranding.
Linking two sites together is the hardest because you have to choose which URLs to stay and which to merge into existing, similar pages.
John Mueller replied:
Unfortunately, while at first this may seem like a small change within a website, it’s not that simple for search engines.
In particular, search engines like Google store their index on a per-page basis.
So if you change the address or URL of a page, the data for that page must be redirected somehow, otherwise it is lost.
It doesn’t matter if you’re rebuilding an entire website or if you’re just removing a slash from the end of URLs. These are all basically site transfers.”
John Mueller provides guidance on site migration
1. Research the options and potential impacts
Site movements can be disruptive, so it is important to plan your move by assigning one site to another. One way to do this is to split the two sites into sections and see if the sections can be mapped to each other.
From there, it’s a matter of mapping URLs from one to another and identifying which URLs can’t be moved to the new site and must be resolved to a 404 response, which can be tricky if there are links pointing to those pages. This is why it is so important to plan ahead thoroughly.
“Because these changes take time and have ranking implications, it is also a good idea to consider the timing of when you make a move.”
Screenshot by John Mueller from Google
2. Create a list of your old and new URLs
This is an important step.
According to John:
“…this tip will help you track changes and check them afterwards.”
A good practice is to create a spreadsheet of URLs, which can be easily done with Screaming Frog.
Once you have the redirects in place and the new URLs, you can verify that they are working by uploading your old site structure list to Screaming Frog so it can crawl the URLs.
This is easily done by selection the situation > List Then click to lift Dropdown tab and choose the type of file being uploaded.
Screaming Frog will crawl the old URLs in the list and show you URLs that redirect to the new URLs that don’t return a page 404 Not Found error code response.
The 404 URLs may be the URLs that did not reach the new site (if they weren’t the URLs that were planned to be dropped intentionally).
You’ll have to determine if the 404 is the correct response (you meant to do this) or if the URL was inadvertently left out of the site migration and needs to be mapped to a new URL.
Related: The Ultimate Guide to SEO Friendly URL Structure
3. Implementation of migration
301 redirects all old URLs to new URLs, and also updates all internal flags like:
- structured data
- and the Robots.txt file
Related: Site migration issues: 11 possible causes of low traffic
4. Immigration control
Mueller advised using Search Console for this:
“Check all pages for redirects. In the Google Search Console report, you should see a quick change for the most important pages and then a slower change as our systems reprocess the rest.”
Mueller warned that this latest part could take months to finish. He talked about how determining the overall site quality can take months. Google has to basically learn about what a site is, including site quality and understanding where a site fits within the internet.
Mueller recommends leaving redirects for at least one year
John from Google recommended leaving redirects in place for at least a year.
In my experience it may be necessary to consider leaving redirects in place for longer than a year. The reason is that old URLs with links from other sites pointing to them will become dead links if the redirects are removed.
You can establish contact with communication sites that link to you and ask them to fix the links to point to changed URLs.
But be aware that doing this kind of outreach can backfire because some sites, for many reasons, may decide to remove the link altogether.
Also, there may be links that you don’t know about, so you can never be sure that all incoming links are updated. For this reason, it may be necessary to keep these redirects in place and be prepared to update them in case some URL changes again, to avoid creating chain redirects.
Chain redirects are a reason you don’t want redirects to be permanent.
A chain redirect occurs when an old URL redirects to another old URL, which in turn redirects to another old URL before redirecting to the final URL link. Over the years, this can create a series of redirects that become problematic for crawling.
Site migrations are difficult
As Mueller advised, it is important to plan ahead. Map similar pages together and be aware about link rights from inbound links. Site migrations can result in a site losing search existence but should not if it was preceded by a comprehensive migration plan.