SEO migration without loss of search traffic is easy

21 February 2022

A good website is never finished, in the same way that your company is ever finished. A website is alive. That is why companies renew their websites either partially or completely every few years. We call this a website migration. If you don’t develop your website or development isn’t executed properly, you can potentially lose up to 80% of your organic traffic. Fortunately, implementing a well-planned and executed website migration means your website can retain its SEO value – and your business will continue to grow afterwards. Read this blog post to find out how that works.

seo migration

What is SEO migration?

During the migration of your website, we 'move' your whole website or a few pages of it to, for example, a new domain or CMS. It’s only an SEO migration if the accumulated SEO value is considered and it is consciously moved. SEO migration goes way beyond redirects and some plugins. After all, a strategic SEO migration takes all sources into account and prevents search engines from reacting negatively to the structural changes to your website.

When is SEO migration necessary?

There is no magic formula that you can use to measure whether SEO migration is necessary because every website is different and faces specific challenges. Naturally there are many different types of migration.

SEO migration is necessary in these circumstances:
  • Major technical or structural changes:

    • New CMS

    • Change of URL structure

    • Transition from HTTP to HTTPS (secure)

    • New shop technology

  • Launch of a new website or platform

  • Merging different domains

  • Taking over a domain name

  • New brand and/or domain name

Any of the above circumstances demand an in-depth risk analysis.

And for every situation there is a migration:

So when we speak of a website migration, we refer to the implementation of any major changes to the website that can significantly affect visibility in search engines. This can be back-end, content or front-end:

seo migration1

A practical example: recently, many companies had to switch from e-commerce platform Magento 1 to Magento 2. A platform migration, in other words. We helped our clients Cavallaro, Babboe and NEVI with well executed SEO migrations.

behoud verkeer na migratie
Perform even better in search results

SEO is everywhere and vital for the modern marketer. We will help you get started with this complete SEO guide.

SEO guide | iO

What should you pay attention to when migrating?

There are a lot of different factors involved in this, so in theory there is a lot that can go wrong with a migration. We are going to list the most common pitfalls here.

Be careful with widgets and technical extras

To maintain rankings, migrated pages must be very similar to the old website’s pages. Therefore, it is important that you pay attention to JavaScript frameworks such as React, because some interactions will only be accessible under their own URL, and it is essential that search engines can read the content easily.

Core Web Vitals

Video, high-resolution images, fun widgets and other fun things that make your content attractive demand extra attention. When it comes to Google's Core Web Vitals, the 3 metrics that connect page speed to UX, mean that anything that has a negative impact on the loading time of your website also has a negative impact on your rankings. It is important that you get good advice.

Take the Google crawl budget into account

Google has a crawl budget for every website: this is the number of URLs that Google can and wants to index. With large websites, the trick is to manage the crawl budget carefully so that Google (for your SEO) indexes, your most important pages well. Migration that ignores this risks a loss of search traffic on your conversion pages.

Pay extra attention to company takeovers, mergers, and name changes

Google is poor at determining whether a migrated domain name was purchased purely for SEO value or is an actual company merger and name change. A poorly executed SEO migration sends the same signals as black hat SEO activities. This type of confusion can be avoided by taking the right steps in the right sequence.

A badly managed migration will result in a domain reset. This means that you lose all your accumulated search traffic and ranking potential. This happened when the department store chain V&D migrated their website in 2015. Their restart as an online department store did not meet Google's requirements for the continuation of a domain name on a new platform. 3 years later, in 2018, the website had recovered the old level despite renewed SEO efforts.

Can you still save the structure when mistakes happen?

Prevention is always better than cure, yet in practice we also regularly carry out retrospective migrations.

If our clients transition to a new website or domain without considering SEO, the consequences can be disastrous. Visitors are shown 404-pages, Google results suddenly lead to non-existent pages and previously high-performing content is not found on the new site. The example below shows what can happen to your organic traffic if you don’t take SEO into account in a website migration:

Traffic loss after migration

The graph illustrates this, we were involved only after the (failed) migration. It is possible to rectify the situation, but the loss ofsix months of organic traffic is obvious.

Common mistakes in an SEO migration

The above example is no exception. We have noticed that more companies are calling iO after they have experienced unexpected negative consequences. The cause can often be found in one of the following problems:

  • Poor strategy with unclearly defined objectives and requirements.

  • Implementing changes in multiple areas at the same time.

  • Lack of resources/budget.

  • Insufficient time for the actual migration and testing.

  • No solid pre-migration analysis, high-performing content does not migrate properly.

In many cases, the underlying cause is that, in practice, for clients it can be difficult to properly brief your development partner. If you are uncertain which parts of your current domain are most valuable, and which parts of your new environment will grow your value, it is easy to overlook crucial elements in terms of content or technology. A website is always a compromise between design and functionality, on the one hand and effectiveness and design for SEO on the other. That is why it’s worthwhile collaborating with an experienced full-service agency such as iO. With all the necessary knowledge in-house, we leave nothing to chance, and a well organised SEO migration can be very (cost-)efficient.

Follow best practices

A new site is primarily an opportunity for growth. Collaborating closely with iO when you are preparing for (major) changes to your site means that we can share our knowledge of best practices easily with you.


  • Avoid discussion by properly mapping out all the requirements for the website and involve development at the earliest stage of the process.

  • Do not migrate front-end and back-end at the same time. If something goes wrong, the cause is easier to trace. For example, first perform the migration to the back end, and then the new web design and site structure.

  • Make time and budget available for development set up a staging environment in which you can test the new site.

  • Test the website for at least 2 weeks in the staging-environment and only go live when everything is proven to work well, and the redirect-plan has been properly implemented.

  • Back up the current site so that you can revert in case of critical incidents.

  • Schedule a go-live on a Monday or Tuesday, so that developers are available in the following days to solve any problems.


  • Mobile first. Navigating and orientation, but also conversion should be possible on mobile.

  • The speed of your website is crucial for mobile users. This is especially true for informational pages that users visit early in the orientation process.

  • Crawling & indexing are essential, so use JavaScript and other interactive elements only when it's necessary, and make sure it doesn't cause any problems for Google or Bing.

Case: A Successful Website Migration for SRO

SRO provides well-maintained, vital, and future-proof sports facilities in various municipalities in the Netherlands. The new website of SRO was launched in April 2019. Due to the close cooperation between SRO, SowiesoHelder (development) and iO, the website migration was very successful. We not only retained (organic) traffic and search results, but we increased traffic, search positions and most importantly, conversions. Some of our achievements:

  • More than ten number-1-positions (organic search results).

  • 34% more conversions.

  • 20% increase in general traffic.

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Need help?

Are you thinking about developing your website and would you like some help? Feel free to contact us. We would love to get together and take a look at how we can help you.

Peter van der Graaf
About the author
Peter van der Graaf
Head Of Search Engine Optimisation - iO

Peter ranks high on keywords like 'expert' and 'evangelist', as well as 'super geek'. Since 1996 he has been studying the most important algorithm in the world, fueled by his main passions: psychology and machine learning. A data-driven storyteller all the way.

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