When doing website migration, or even just content migration, a lot of companies experience problems such as decreased traffic. Depending on the nature of the business and the website and their previous traffic level, companies can lose quite a lot of traffic and, ultimately, revenue.

Migration can be switching from one CSM to another or moving the entire website, i.e. building a new website. Switching to a different version of a programming language or adopting a new programming language is also considered a form of migration.

Here’s how we can classify the types of website migration:

  • Migration of a CMS from one hosting to another
  • Migration from one CMS to another CMS
  • Look & Feel
  • Migration of the backend
  • Migration to a secure site, from HTTP to HTTPS
  • Migration of the software version of the site or other parameters within the hosting or server where the website is hosted.

What can a website migration affect?


The new system may automatically generate new URLs with the database content, and in that case, the old URLs will be lost.

If this is the case, you may end up losing all traffic, or a fraction of it. Your old URLs are already indexed, so if they are not redirected to the new ones, they will appear as 404 errors which will indicate that the pages aren’t there anymore. Your pages will start disappearing from Google, which will pave the way for your competition to assume the positions that were initially held by your pages. 

If you are convinced of the quality of your site architecture and you are satisfied with the URL length, you can keep the structure that’s in place and you won’t have to take an unnecessary risk and change them. 

You should pay attention and go through the new configuration to see if your server allows uppercase letters, how the slash (\) affects the end of the page and most importantly, whether these things will automatically be changed. If that is the case, you might end up realizing how everything has changed when it’s already too late and the damage can’t be undone. 

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Web Page structure - on-page optimization

This applies to the case when content is migrated to a new CMS, or the template or theme are changed while retaining the same CMS. 

Here we will differentiate into two parts, internal (content for Google) and external (content for users). For better understating, we differentiate the content as internal (content for Google) and external (content as presented to users).

When speaking of content for Google, you need to verify that the meta tags that you’ve previously used continue to be generated and that there isn’t a big change in the template. 

You may lose tags, formatting, and links when changing templates and this is something you should bear in mind, as it may affect your content and your on-page optimization in general. Keep track of the changes that appear and make sure that you can identify when something has changed and how the new situation is different from the previous. That way, if you see a decrease in traffic you will know what has changed and you’ll be able to establish the possible causes. 

The content that is not shown can be considered to be secondary by Google and if it is loading slowly it may not be accessible to Google and therefore it might not get indexed. Furthermore, you may also lose some of your formatting like H-tags, italicized words, etc. 


The new hosting may not have compression or caching enabled, so even if everything else goes well, you can lose a lot of traffic due to server settings. 

In very competitive SERPs (search engine results pages), speed can affect position, i.e. your pages can drop in positions dramatically if loading times increase. 

Other relevant factors

We should highlight the important role of canonical tags, as these may be erroneously leading to non-existent pages and thus have a detrimental effect on your site’s ranking.

The mobile version of your site is another important factor, especially since Google’s mobile-first update. 

There are other matters that you should consider. When introducing a new version of the site software, some of the instructions may not run properly. Also, migrations of databases can cause problems with user permissions. These things happen, you should be aware that such problems may arise and be ready to deal with them accordingly. 

If you’re using analytics tools to analyze traffic and website visits, be aware that the traces and records made by the tool might not appear when the site is migrated which will cause a discrepancy in traffic figure. Here’s a record of that:

Once reviewed the main points that can be affected, let's move on to the cases that we have mentioned initially and how they affect the SEO: We have specified the key areas that can be affected, now let’s have a look at the cases that we mentioned initially and the impact they can have on SEO.

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Migration of a CMS from one hosting to another

This is the type of website migration where we want to move our WordPress or Drupal site from one hosting to another for more space, for hosting features (speed, stability, ...), etc.

The most important thing is to keep a copy or a backup version of the entire site. That way, once you move it from one hosting to another you will be able to check if everything is migrated properly and if not, you can go back and fix the errors.

Does it affect SEO?

Ideally no. If only the web site moves and everything stays as it is, there should be no problem as the URLs will remain the same. You should verify that the server configuration is the correct one, check loading speed, and see if the software version of the site can be integrated with the server configuration.

The advantage of this type of migration process is that we can see the new site, see if access is possible, make the necessary verifications and then change the DNSs with the ones you got from the new hosting.

Migration from one CMS to another CMS

One typical example of this type of website migration is when you have a WordPress site and you want to switch to Drupal. But it also includes moving from a CMS to a custom HTML5 platform, or when you’re switching from an e-commerce site like Shopify to a dedicated site, i.e. when you decide to open your own e-shop. 

When it comes to SEO and the effect a migration can have on it, this is the most severe case, as this type of migration has an impact on what the site looks like and the system that’s behind it. 

Does it affect SEO?

As we said, yes. Some URLs might be modified due to the new CMS. For example, if you’re using Joomla you can find /index.php/ placed in the middle of all your URLs.

This is practically a new URL, and if you want to change it, you might face a situation where the new URLs are already indexed whereas the old ones appear as 404 errors. This situation can cause problems and hurt your rankings. 

As the site front-end will inevitably change, certain content errors might appear, not to mention that some plug-ins that are available on one CMS may not be offered elsewhere, which can cause additional problems. How you approach on-page optimization might also need to change. 

If your new CMS uses another software solution, you will need to pay attention to its configuration and operation. Sometimes automatic configurations on one of the CMSs can cause you severe headaches. For instance, the configuration of the tags and categories on your old CMS might not be reflected properly in the new one. In this case, you might have to go back to the copy/backup version of your original website and redirect the URLs.

Look & Feel

This phrase implies the exact thing it says - the look and the feel of your site will change. It can be done from the CMS, or directly from the CSS. 

Does it affect SEO?

Yes, it affects SEO, especially on-page optimization. You should do your homework before you go through with the changes and know what is about to be removed or changed, so you can establish the necessary steps for a successful recovery. 

Sections or parts of your site may automatically disappear, and new sections might appear, also automatically. Let’s say that you had a portfolio section on the CMS - it may disappear with all URLs resulting in 404 errors. 

To solve this sort of an issue, you should have a list of old and new URLs and start checking which URLs result in 404 errors and start redirecting them. You can find the URL list in Google Search Console.

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Migration of the backend

Plain and simple - this is when you migrate the back-end of your site, i.e. when you switch from one back-end system to another. 

This is maybe one of the most harmless migrations from an SEO point of view and yet it can be quite annoying. 

For example, a change of the back-end of an e-commerce site can cause the catalog URLs or some of their elements to disappear, thus causing them to lose their positions or internal links. Both can harm your domain authority and site relevance.

Does it affect SEO?

As we already said, you should check the behavior of the new back-end in terms of URL and data creation. To be more specific, you should see if some URLs are lost and check how data is generated.

If the migration to a new back-end causes problems in terms of generation of search queries that might increase the loading time of the website and that can have a detrimental effect on SEO as we mentioned above. 

Migration to a secure site, from HTTP to HTTPS

This type of migration is becoming an imperative for many companies. The reason is double - not only does your site become secure, but encryption is also one of the factors that are considered by Google’s algorithm. 

This is not a very complex change, but you should be careful because if something goes wrong and the migration isn’t done properly, the HTTP and the HTTPS version can coexist simultaneously which might confuse Google. You may wonder what that could mean, but it simply means that Google will not know which version has priority and as a result, it will not obtain the rankings of one of the versions. 

Does it affect SEO?

Definitely, yes! If it’s done well, usually links are obtained from the HTTP version of our website. If they are redirected via 301 from the old HTTP pages to the new HTTPS pages, the links might lose relevance due to the redirecting.

In the worst-case scenario, the redirecting of links from the HTTP to the new HTTPS can cause a huge amount of organic traffic to be lost and that can have a negative effect on your business. Even if it’s just protocol migration (without any change of the URLs, no new CMS or a change in the site look & feel), the changes that are caused by this migration can generate duplicate URLs, duplicate content. It is also possible to have canonical tags that point to wrong URLs or internal links that still point to the old HTTP version. 

Migration of software version of the site or other parameters within the hosting or server

This type of migration is basically caused by your hosting provider and it can affect either site software or space, or both. 

We recommend having a good CDN (content delivery network) always at hand so that you can have a copy of your site accessible on other nodes or servers, or at least a good backup version so that you will be able to restore it as quickly as possible if the need for that arises.

Does it affect SEO?

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Normally, this type of migration shouldn’t be a problem. If you check the terms and conditions of your agreement with the hosting company there must be a section where the maximum offline time before there are penalties for the hosting company is stated.

Still, you should be prepared, keep a backup and be ready to get to work to recover your site in case of a failure of a software update or a similar situation. The difficulty and complexity of such a recovery depend on the site of your website, some sites can be recovered from a copy kept on your laptop, but larger sites will need a more complex recovery system, perhaps even the above mentioned CDN might be necessary. 

Changes or updates of plugins within CMSs can also be included in this type of migration. For example, the site is stable and when you upload and activate a new plugin it suddenly goes offline. 

Migration is a challenging yet rewarding experience when done right. As we can see, there are a few common SEO problems that may occur in the process. These problems can affect the links, the keywords, the speed, the design and these can drive down traffic, leads, and conversions.  Therefore, you should consider the impact on SEO when you are about to migrate your website.

For that purpose, we have prepared an SEO migration checklist that you can use as a guide in order to ensure that changes occur smoothly: 

  • Consider SEO and the possible effects  from the start

  • Crawl the current site/version of the site)

  • Audit the current site/version of the site

  • Make sure that the staging site is NOT indexed by Google

  • Crawl the staging site

  • Make sure that every page has meta data

  • Check for 404s on the staging site

  • Map old-to-new URL redirects (301s)

  • Make sure that your robots.txt file is not blocking search engine bots

  • Check for duplicate HTTP and HTTPS pages

  • Check for duplicate www and non-www pages

  • Make sure that every page has a canonical tag

  • Make sure that pages that need to be indexed don’t have the meta robot “noindex” tag 

  • If you’re using Google Analytics or other tools make sure that all the pages have a tracking code.

  • Submit the new XML sitemap to Google Search console, so the search engines can crawl the site properly

  • Launch!