SEO migration: maintain your top search engine positions

After reading this article, you will understand:

• The impact of an incorrect or missing SEO migration on your search engine rankings and traffic.
• Why you need different types of SEO migrations, depending on your situation.
• The five essential phases for successfully carrying out a SEO migration.
• How different factors can boost or hurt your organic traffic in the long run.

What is a SEO migration?

A new domain name, different URL structure or switching to a new CMS? A SEO migration requires a thoughtful approach. If you do it wrong, you will lose your findability in Google. But do it right? Then you not only maintain your rankings, you even improve them.

The moment you make a lot of structural changes within your website, this also changes the situation for Google. Helping Google understand this situation We call SEO migration. Structural changes and so different types of migrations that fall under here are, for example:

• You move your website to a new domain.
• You switch to a new content management system (CMS).
• You change the structure of your website.
• You customise the navigation or user experience.
• You give your website a complete redesign

Do you leave a mistake? Then you'll see your traffic and conversions drop. It often takes months to recover from that. Fortunately, you don't have to do this alone - we're happy to help!

Website migrations can happen in a variety of ways. Consider rebuilding your website, moving to a new domain, merging with another site, switching from HTTP to HTTPS, or a combination of these. Further on, you can read how each type of migration works.

The importance of a SEO migration

Creating a well-optimised SEO website takes time and attention. Every change on your site affects how Google understands and indexes your pages. Does a migration go wrong? Then you risk less traffic, lower rankings and lost sales.

Yet sometimes a migration is necessary. For example, to make your site faster, more secure or more user-friendly. We will help you with a plan that protects your rankings, traffic and conversions.

How does a SEO migration work

Is your website growing? Then your technical environment changes with it. Sometimes you switch to a new CMS, domain or structure. This is called a SEO migration. Zonder a smart plan, you quickly lose valuable traffic, such as visitors who land on your best-scoring pages via Google.

Keeping traffic and positions? Here's how to do it

Proper preparation prevents problems. A thoughtful SEO migration will temporarily cost some traffic, but will ensure better positions afterwards. Zonder strategy you drop in Google and visitors drop out. You want to avoid that

Work out a clear roadmap in advance. A checklist will help you not forget anything. Think: test redirects, submit sitemap, check tracking codes, and check indexation. We will elaborate on this later in this article

Reasons for a SEO migration

A website migration can be necessary for several reasons, especially for companies that want to continue to grow and adapt to new opportunities. Once a company begins to scale and further develop its vision, it will inevitably reach a point where a move to a new site is needed.

A website migration means directing users from your old website (point A) to a new website (point B). If this process is not done carefully, you will lose the accumulated authority and relevance of your old website. This can lead to a loss of traffic when visitors are sent via old links to non-existent pages, rather than to your website's new addresses.

There are several reasons for SEO migrations:

• Website move
  Are you moving to a new domain or from HTTP to HTTPS? Then your entire URL structure will change. Make sure you have proper redirects so that you remain easily findable.
• Choosing a new CMS
  A new content management system often makes your site faster and more flexible. Think shorter load times and better SEO options.
• Switching to another top-level domain
  Moving from .nl to .com? Then you are changing your online identity. This affects your findability abroad and your brand position.
• Customise URL structure
  Want to build your URLs differently? Plan this carefully. Avoid SEO loss: set up redirects and update your sitemap.
• Merging websites
  Do you combine several sites? Then bundle authority and simplify management. Keep the structure clear and avoid duplicate content.

Want to know exactly what these changes mean and what to look out for? Hereonder we go over each point. You'll read what the impact is, where the risks lie and how to avoid damaging your SEO or user experience.

Website relocation

A website move occurs when a site moves completely to a different URL and may consist of the following changes:

Switching from HTTP to HTTPS
You are switching to a secure connection to better protect data. This is important for SEO, for the trust of your visitors and to comply with legislation such as the AVG.

Changing your domain name
When rebranding, merging or if your domain name no longer fits your brand, choose a name that better suits your identity and target audience

.Moving content from subdomain to subfolder
For example, from blog.example.co.uk to example.co.uk/blog. This way, you bundle your website's authority and improve its structure with SEO advantage as a result.

Switching from .nl to .com
If you go international, you often choose a .com domain. It looks more professional and appeals to a wider audience.

Adjust URL structure when repositioning
You adjust your URLs as your offerings change. For example, from services/seo to solutions/search engine optimisation. This provides more clarity and better matches your new positioning.

Switching CMS

A CMS move seems simple, but it often has major consequences. Think of your URL structure: it usually changes and that affects your findability in Google. The design also often has to be rebuilt, especially when switching to a platform with different technical capabilities.

In addition, check your internal links, redirects and content migration. Fail to do so and you risk broken pages and losing valuable SEO results. Want a smooth transition zonder loss in rankings? Get guidance from specialists experienced in CMS migrations and SEO retention.

Merging websites

Bringing multiple domains together into one is technically and strategically challenging. What seems simple soon becomes a project lasting months. And in that time, there are countless moments when things can go wrong.

Just one wrong redirect or forgotten URL can cause:

• drop in your organic traffic
• poor findability in Google
• loss of accumulated authority
• frustrating error messages for your visitors

This is how you keep control of your SEO value

With a good plan, you avoid costly mistakes:

• Redirects in order. Make sure each old URL points to an appropriate new page.
• Technology check. Think loading speed, indexation and whether Google can read your site properly.
• Taking all content. Don't just delete pages or shorten texts. Less content means less SEO value.
• SEO continue to follow. Measure traffic, positions and errors before, during and after going live.

Leave nothing to chance. One forgotten step and you sink in the search results just like that.

The SEO migration plan in steps

To perform a SEO migration successfully, it is best to follow a step-by-step approach: We will guide you through each stage and explain exactly what we are doing, why we are doing it and what you can expect at each step.

Phase 1: inventory and analysis (pre-migration)

We collect all important SEO data: URLs, backlinks, meta titles, meta descriptions, headers, alt texts and response codes. We always back this up. Does something go wrong during the migration? Then we can switch quickly.
We then transfer all this data one-to-one to the new site.

We also do a baseline measurement: which pages are currently generating traffic or conversions? This allows us to see immediately after going live whether the migration is working as intended.
We plan the go-live period deliberately. Not during busy periods and certainly not on Fridays. Solving problems at the weekend is simply inconvenient. Rather on a quiet day - Tuesday or Wednesday - so we can intervene quickly if needed.
This approach reduces your risks and keeps your SEO performance stable.

Phase 2: preparation (pre-migration)

We start with a complete overview of all current URLs, PDFs and images, including their SEO value.

We map that SEO value by looking at data such as organic traffic, keyword positions, backlinks, load time and click frequency. We also analyse which pages generate conversions. That way, we know exactly which content is important for your visibility and turnover and what absolutely must be preserved during the migration.
That overview forms the basis for a logical and future-proof URL model for the new site. We then link each old URL to a new one via a clear URL mapping. For each old URL, we set up a 301 redirect so you don't lose traffic or authority.

We also work out technical guidelines for the new site. Think of crawl settings, canonical tags and metadata. We deliver these specifications to the web builder or developer in good time, so that everything is technically correct and Google can index your site properly.

We always recommend including SEO in the plans for a new website or changing website, but it is not necessarily necessary. Think, for example, about discussing a new structure or taking stock of which content should be brought to the new situation. However, making preparations for a SEO migration is necessary. The onder parts in this preparation and planning phase are:

• Agreeing a date for going live, preferably in the off-season in terms of website business
• Doing a comprehensive baseline measurement of search term positions of current search terms
• Analysing all existing backlinks
• Performing a comprehensive crawl of the current website with as much input as possible from sources that know URLs from your website (Search Console, Google Analytics, Ahrefs, etc.)
• Creating a URL summary from the crawl with any SEO value per URL added to it
• Creating a URL model of the new website + possibly arranging access to a test environment

No website migration is the same, but these are generally the most important steps in this phase. Obviously, it is also very important to make good planning agreements together (website owner, SEO specialist and web builder).

Phase 3: test phase (pre-migration)

Once all 301 redirects are set up, start the testing phase. This is still within the pre-migration phase. During this phase, you check that each redirect works correctly and does not generate any error messages. This prevents technical issues once the site goes live and therefore SEO losses. Because does the redirect not work properly, or do error pages persist? Then that can have a direct impact on your findability.

We also test whether search engines can crawl the site without any problems. This way, we prevent technical errors that could directly harm your visibility. Because if redirects do not redirect properly or error pages persist, you miss out on SEO value.

Also test the mobile usability of the new site. Google judges your website primarily on mobile performance. So make sure that content, navigation and loading time also work well on mobile. With thorough testing, you avoid surprises afterwards and protect your performance in Google. Read more about what to look out for in a good technical basis via our page on technical SEO.

The onder parts of this phase are:

• Creating a redirect file for URLs that change: link old URLs from the URL overview to new URLs from your URL model
• Adjusting the internal links in the test environment based on URLs that are going to change
• Auditing the test environment (checking for crawlability and indexability, as well as SEO elements such as text, meta titles, etc.)
• Fixing a good 404 page
• Fixing a new XML Sitemap and preferably also an 'old' XML Sitemap containing all the changing old URLs
• Testing your redirect file in the test environment. Check that all redirects work and point to the correct destination URL
• Informing other stakeholders. For example, share the redirect file with your Google Ads agency and email marketing/automation agency

Phase 4: going live and testing (post migration)

During going live, you activate the new website. This phase falls onder the post-migration. Make sure the site is temporarily inaccessible to visitors and search engines alike by setting a 503 response code. This indicates that onderhoud is taking place, so that Google knows the situation is temporary and does not immediately reindex your site.

Also, make sure the site is not accidentally indexed before everything is checked. You do this, for example, with a temporary noindex tag. As soon as the site is live, immediately check that all the technical elements are working properly: redirects, metadata, canonicals, XML sitemap and robots.txt. Only if everything is correct do you remove the noindex tag and remove the 503 status.

Also test whether all content and functionality have been transferred properly. Also check the speed of the new site using tools such as Google PageSpeed Insights. Use a clear checklist to take a structured approach and identify errors quickly. We use our own SEO migration checklist.

In summary, it is important to include the following points at this stage:

• Agreeing with the entire project team on when to go live (preferably not on a Friday). And whether it will be a soft launch (going live for a selection of users) or hard launch (going live for everyone)
• Checking Robots.txt and X-robots or Meta robots (noindex, nofollow)
• Submitting XML Sitemaps in Search Console
• Crawling all old URLs known from previous crawls
• Crawling the new website (often we do the above steps in one)
• Doing a 'Change of Address' in Search Console (only when migrating from domain to domain)

Phase 5: monitoring (post-migration)

This phase falls onder the post-migration and starts immediately after going live. You closely monitor the performance of your new website. Use tools such as Google Search Console and Google Analytics to actively monitor data from the new environment. Look out for signs of errors or deterioration, as well as improvements.

Important measures to track over time are onder others:

• changes in organic traffic
• fluctuations in search positions
• changes in the bounce rate
• increase or decrease in conversion rateBy regularly analysing this data, you can quickly see whether the migration went well technically and in terms of content, and you can make adjustments in time if necessary.

Apart from the fact that SEO is a continuous process, you can also adjust your SEO migration at this stage. You can do this by:

• Fixing (301 redirecting) all 404s that come in from the crawl or in Google Analytics and Search Console
• Briefing the developer on bugs (technical SEO issues) that come out of the crawls of the live environment
• Keeping an eye on the Index coverage report in Search Console
• Monitoring results (rank tracking, Google Analytics, Search Console, etc.)
• Updating important backlinks if you have contact with the owners of the websites on which they can be found
• Making a plan on how you will further up the SEO positions after going live

SEO migration tips

With a few clever tricks, you can make a SEO migration a lot clearer and more manageable. This way, you avoid mistakes and keep a grip on the process. For instance, first set up a test environment so that you can safely test whether search engines or users will notice. Perform the migration in phases if possible to minimise risks and make quicker adjustments. And don't forget the backlinks: check which links are valuable and which you should keep in the new structure. A thorough audit helps you properly identify risks in advance. These tips will ensure that your SEO performance remains stable during and after migration.

Create a test environment

Provide a separate test environment where you can fully test the new website before going live. This environment should not be accessible to search engines, customers or users. Put it behind a login or IP whitelist, for example. This will prevent Google from accidentally indexing test pages or visitors ending up on an incomplete site.

In this secure test environment, you can extensively check all functions of the website: test whether redirects work properly, check whether the content is displayed correctly at the frontend, and assess the user-friendliness of the site. By doing this in advance, you avoid mistakes when going live and surprises.

Website migration in parts

Migrating a website all at once is often complex and error-prone. By dividing the migration process into parts - e.g. per section, type of page or subdomain - you maintain overview and control. You can make adjustments faster if something goes wrong, because it is easier to pinpoint the problem. Moreover, you reduce the risk of large-scale SEO loss. A phased approach makes the whole process manageable and increases the chances of a successful transition.

Conduct authority audit

Check your website's domain authority before and after migration. This will give you insight into any changes in your backlink profile. Check whether valuable backlinks have moved correctly from the old to the new site and whether they still point to working pages. Also pay attention to the origin of the backlinks: are they still coming from reliable and relevant domains? A sudden drop in authority could be a sign that important links have been lost. Want to actively work on a strong backlink profile? Then check out our approach for linkbuilding.

Using crawl tools

Use tools like Screaming Frog or Lumar to quickly detect technical problems after going live. With a crawl, you can see at a glance whether all new URLs work, whether redirects are set correctly and whether there are errors in metadata or canonicals. This makes it ideal for checking whether the migration has been implemented properly technically.

These tools are also useful during preparation. They allow you to easily export existing URLs and use them when preparing your URL mapping. Is it a large website with more than 100,000 pages? Then use a cloudbased crawler such as Lumar. This crawls your site via the cloud, so your computer does not have to be switched on and you process large amounts of data faster. So you keep a grip on technical SEO, zonder slow down your workflow.

Google Analytics

Set up Google Analytics 4 (GA4) even before your website goes live. This way, you immediately establish a baseline measurement. After the migration, you can then immediately check whether everything works as expected zonder additional costs.

GA4 is a free tool from Google that gives you insight into visitor behaviour on your new site. This is essential after a SEO migration.

With GA4 you can:

• Tracking traffic on your new URLs
• Discovering changes in user behaviour
• Seeing if your organic traffic is increasing or decreasing
• Comparing results before and after migration

This way, you will quickly know whether your website is performing well and where you may need to make adjustments.

 Google Search Console

Want to keep a grip on the performance of your website after a migration? Then use Google Search Console (GSC). This free tool from Google shows how your site ranks in search results.

Technical bugs you want to get to the surface quickly. Think crawl problems, 404 errors or pages that are suddenly missing. GSC will point out exactly where the friction is, so you can fix it immediately.

GSC also provides an overview: you see how often your site is displayed, how many clicks you get and whether your positions have changed. That's how you find out if you're doing well, or if you need to take action. Important: don't forget your XML sitemap. Make sure you upload an up-to-date version as soon as your new site is live, and submit it via GSC. That way, you'll help Google index your pages quickly.

In short: set up GSC right away. It is your dashboard for technical control and visibility. It is indispensable after a migration.

URL in ads

With a website migration, your page URLs change, but this change is not automatically reflected in your ad campaigns. Therefore, check carefully whether all links in your ads still point to the right pages. This will avoid error messages and loss of traffic and budget.

Internal linking

Think of your internal links as your website's signposts. If you don't include them after a migration, Google will literally lose its way. The search engine follows your internal links to discover and index pages. Are they no longer correct? Then Google will get no further than the homepage and that can cost you positions. So make sure every link still works and leads to the right place. That way you keep your website findable and logical.

Robot.txt

A new website? Then a fresh robots.txt-file. Think of it as a kind of access card for search engines: in it, you specify which parts of your site they can explore, and which they cannot. Do you leave this old file in place, or forget about it altogether? Then Google can get lost, skip pages or actually index sensitive content you would rather hide. So make sure you have a new version with up-to-date instructions, tailored to your new URL structure. That way, you stay in control.

Ready to safely migrate your SEO value

A SEO migration is not a technical sideshow, but a crucial step in the growth of your website. Think of it as moving a well-run shop: if you don't properly communicate directions, signage ánd opening hours, your customers will stay away. It works the same way online.

Therefore, a structured approach is not a luxury, but a necessity. Do you want internal links to keep working properly, ad links to be correct, redirects to run smoothly and tracking and indexation to run flawlessly? Then that starts with a smart plan and careful execution.

Onder helps with SEO migration

A SEO migration is not a matter of flipping a switch. It is an intensive process that combines technology, timing and strategy. Whether you are switching to a new CMS, changing your domain name or merging several websites: every change can have consequences for your findability. Onder guides you step by step from analysis to going live and monitoring, so you do not lose valuable positions, which is why it pays to outsource this job to a specialist. We do this every day, we know every scenario and we know where things often go wrong. You don't have to reinvent the wheel yourself. Want to make sure your migration runs smoothly? Then ask us today for a no-obligation  advice. We are ready to think with you before Google loses it completely for a while.

Examples of our SEO migrations from practice

We at Onder do a lot of SEO migrations, from large to small and complicated to uncluttered. We highlight three migrations of recent times

Example 1: Daka

Daka is a chain of sports shops + a fairly large webshop. They specialise in many product groups and are particularly strong in winter sports items. Daka's marketing team knocked on our door to onder support in the webshop migration that was upcoming.

• Platform migration from Xsarus TableTop to Magento2
• Many changes in URL structure + a changing product URL structure
• Redesign + code changes
• Many URLs: before going live the number was in the tens of thousands

Daka's new situation was so different that Google did struggle with it at first, but after adjusting with technical changes and content additions, we had an upward trend again, just in time for the post pandemic winter sports season of early 2022.

Example 2: Industore

Industore is a technical wholesaler with a sizeable webshop. Industore specialises in a number of niche markets and is therefore particularly findable on technical products. Organic traffic is important for Industore.

• Platform migration from a custom platform to Opencart
• Few changes in URL structure
• Code changes and many technical SEO improvements

Industore was also a typical migration by the book: all onder parts were tightly finished by ourselves, Industore and the connected developer. Still, you see a small dip after going live followed by a nice increase in organic visibility.

Example 3: Internetvergelijk.nl

Internetvergelijk.nl is a comparison platform for internet, television and telephone subscriptions. The platform relies heavily on organic traffic and was and is highly findable on a variety of search terms that match the target audience's orientation phase.

• Changes in URL structure during this migration
• Redesign + layout changes
• Transition from HTML to JavaScript framework (which we fortunately found out about in time)

The most exciting aspect of migrating Internetvergelijk.nl was the transition from pages in HTML to a JavaScript framework. Fortunately, we were able to test extensively in the test environment with a Prerender solution that still works well. The transition is hardly noticeable in the results, as organic traffic is still rising.

How can we help: our SEO migration services

We see SEO as a craft and the SEO migration service is very much a onder part of that. So we are happy to help you with that. Every website and every situation is different, so no matter how structured we implement migration plans: a SEO migration is tailor-made. We help many customers with SEO migration on the following three variants:

1. A comprehensive SEO migration plan incl. implementation: we take a lot of work off your hands with this, because we create the redirect files ourselves in this case and are leading when it comes to the migration project
2. A SEO migration plan based on advice: the focus in this variant is on advice: the executive part lies with you as the client. That we brief exactly what needs to be done, check and deliver extensive output based on crawls is of course beyond dispute
3. SEO migration after going live: you can also 'clean up debris' after going live. Website owners regularly knock on the door who have lost some of their traffic by not taking SEO migration into account. Retrospectively, through technical changes and content modifications, a lot can still be saved.

Are you new to the world of search engine optimisation or looking to improve your current strategy? Start with our comprehensive SEO check to make sure you're doing all the basics right. For a thorough evaluation of your website, check out our Live SEO analysis and SEO analysis website. If you have questions about specific terms. 

Can we help your organisation with this? Then get in touch with us!

Getting started with a SEO migration yourself: the checklist

We are happy to share our knowledge with you. So would you like to get started yourself with a SEO migration checklist and follow our step-by-step plan as you see fit? Then download the SEO website migration checklist from Onder. Success not guaranteed of course 🙂

 Blogs about SEO migration

• SEO migration fuck-ups

• The ultimate SEO migration checklist

• Analyse a failed SEO migration in 6 steps

• Why SEO migrations unfortunately still often go wrong

• Redirects: Hello Google, we have moved

SEO migration cases

• SEO migration shelving unit.co.uk

• SEO migration for Zehnder

• SEO migration for Shift to Solar

Knowledge base articles on SEO migration

• SEO migration: The guide to a website transfer

• WordPress website migration

• What types of website migrations are there?

• Help with a SEO migration: This is what a SEO agency can do for you

• How to properly transfer SEO value during a website migration?