Domain Migrations: Surviving the "Perfect Storm" of Site Changes

Posted by Ruth_Burr

Last week, I held a Mozinar talking about the SEO steps involved in transitioning from to, and sharing some of the results we got. We got some great questions on the Mozinar, and I wanted a chance to answer some more of them as well as expand on some points that didn’t fit into the Mozinar.

Throwing Best Practices to the Wind

As we spent more than a year planning the transition from SEOmoz to Moz, one thing I wanted to make sure everyone knew internally was that we were engaging in — well, maybe not worst practices, but we were pretty far away from best practices when it came to domain migration.

One thing most SEOs will tell you about domain migration is that you shouldn’t make a lot of big changes at once. For example, if you’re switching to a new domain, just switch domains; don’t try to change anything else at the same time. If you’re refreshing your design, just do that; don’t try to change your content or URL structure at the same time. And definitely, definitely don’t change anything else if you’re changing your top-level domain (TLD).

Screenshot from “Achieving an SEO-Friendly Domain Migration – The Infographic” by Aleyda Solis

Avoiding making this many changes to your website at once will mean that search engines have a much easier time finding, crawling, and ranking your new site, and that you’re much better positioned to diagnose problems as they arise.

Nevertheless, there we were: plotting a massive re-brand, site redesign, content overhaul, and domain change — complete with TLD switch — all at the same time. A perfect storm. It’s enough to make a person lose sleep (I know I did). At the same time, I’m glad we went through this, because it’s exactly the kind of thing some of you are going to end up dealing with as well. We needed to make all of these changes simultaneously in order to do what we wanted to do with the new product and re-brand, and that took precedence over SEO best practices. Instead of throwing up my hands and saying “well, we’re doomed,” I had to learn to do as much as I could with the situation at hand.

Doing the Long, Boring, Hard Work

The major portion of my work preparing for the domain migration was my big giant list of URLs:

Casey helped me pull a list of every URL on the site from our database, and I found each URL a redirect target on I would recommend pulling your URL list from your own database or server logs if it’s at all possible; it will give you a much more complete list of URLs than simply running a crawl using a program like Xenu or Screaming Frog.

When I talk to people about the migration, they typically blanch at the big giant list of URLs. Is it really necessary to look at every URL on the site?

Well, no, not totally. In our case, there were large sections of the site (like the blog and Q&A) that were staying largely the same — we could just redirect everything at* to* without needing further detail. For sites that are simply changing from one domain to another without a major redesign/restructure (which, again, you should really do if you can), it becomes even easier: If your site’s staying exactly the same, you can just redirect everything to the same folder location on your new domain.

I’m so glad that I did go through every page on the site, though, since I was able to get rid of a lot of old orphan pages, and help make sure the new site taxonomy was more inclusive so we didn’t have new orphan pages going forward. A site migration is a great time to 301 old pages that have outlived their usefulness to newer, more useful resources.

Traffic and Ranking Loss

I can’t stress enough how important it is to manage expectations around traffic and ranking loss during a domain migration. In the Mozinar, I mentioned that some PageRank is lost through 301 redirects (thanks Ethan for sending along this video from Matt Cutts explaining that the amount of PageRank that dissipates through a 301 is currently identical to the amount that dissipates through a link). This is usually not a huge deal for your most popular, best-linked pages, but can be an issue for deep pages that rank for long-tail terms, especially if the external links pointing to those pages are old or there aren’t very many of them.

With the Moz migration, the site restructure meant that we changed the internal link juice flowing from page to page as well. In some cases that was beneficial, such as with our Learn section which gained importance as it moved from our footer to our (now-reduced) header. In other cases, however, it meant some pages losing internal link equity. Again, not a huge issue for the most important pages but definitely impactful on long-tail terms. Between those two factors, the chance that our traffic and rankings wouldn’t be affected was pretty slim — and they were.

Better User Engagement

The flip side to the traffic loss was that we saw a boost in engagement metrics. Cyrus ran a quick study on a subgroup of users who a) had arrived through non-branded organic search and b) were new visitors to the site, to mitigate as much as possible the influences of preconceived expectations and industry “buzz” surrounding the re-brand. Here’s what he found:

As you can see, nearly every section on the site saw a boost in pageviews and pages per visit, as well as a huge decrease in bounce rate. The only downside is that we did see a decrease in time on page, pretty much across the board. We have a few theories on that: It could be that the more people click around the site, the less qualified each page view becomes; or it could be that the redesign has, in many cases, made pages shorter and easier to read quickly. The fact that time on page has decreased while average visit duration and bounce rate have improved points to the lowered time on page not being an indicator of lower quality, so that’s good.

What About Changing Platforms?

I didn’t get much of a chance to discuss changing CMS/Platforms in the Mozinar, because we run the site on a custom back end and CMS. It’s a question we get a lot in Q&A, so I wanted to address it.

Like most domain migrations, it’s important to keep things as much “the same” as possible when migrating to a new platform or CMS. Ideally, your site would look pretty much the same to users before and after the change – you could start making improvements using your brand new shiny CMS after the migration takes place. One thing that’s especially important to avoid when changing platforms or CMS is to make sure the new back end isn’t appending extra things to your URLs. For example, you want to make sure your home page is still and hasn’t switched to or the like. Also be on the lookout for extensions such as .html or .aspx being appended to your old URLs by the new platform. That’s a really common cause of duplicate content on a new platform.


In the Mozinar, I mentioned that we had multiple sitemaps in Google Webmaster Tools, and got a question about why we do it that way. Since that’s a decision that was implemented before I came on, I wanted to make sure I had the whole answer before I responded, but it was as I suspected. We have separate sitemaps for our blog, Community profiles and YouMoz because those are three of the largest areas of our site. Since each sitemap can only contain 50,000 URLs, this multiple-map experience ensures we have plenty of room in each one for these prolific sections to keep growing. Kate Morris wrote a great post on using multiple sitemaps a couple years ago; you can read it here.

Noise in the Signal

“This is great info, Ruth,” I can hear you saying, “but why did it take you a month to share it with us?” A lot of the reason has to do with noise in the signal.

In the days surrounding the launch, we had increased buzz from our PR efforts and excitement from our customers about the new site. We knew this would happen – and were happy about it! – and that this uptick wasn’t a good indicator of how the new site would perform in the long term.

I also wanted to wait until SEOmoz pages were no longer ranking (as I mentioned in the Mozinar, they’re still indexed but aren’t ranking for any of our target terms) and had been replaced with URLs, to get a better sense of how our rankings were impacted before I shared the info. This kind of longer-term analysis is important in the wake of a migration; make sure you’re getting as accurate a picture as possible of your new metrics.

Thanks again to everyone who listened in on the Mozinar, and who sent your kind wishes and congratulations to the Moz team during this process. It was a huge effort by the whole company and we’re so happy to share it with you!

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July 3, 2013  Tags: , , , , , ,   Posted in: SEO / Traffic / Marketing

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