Website Migration SEO: How to Protect Your Rankings

You’ve worked on a new website, and it’s WAY better than the last one. But as soon as you launch, your search engine rankings fall off a cliff. It’s a story as old as… search engines.

And some sort of rankings impact is unavoidable. But there’s also no reason why your rankings should drop through the floor. If your migration has been thorough, any rankings dip should recover pretty quickly, before returning to or even surpassing previous levels.

In this guide, we'll cover the different types of migration and their risk profiles, why website migrations impact search rankings, why it so often goes wrong, why it doesn’t have to, and - most importantly - how you can protect your rankings with a structured approach to migration.

But first, a bit of background…

 

What is a Website Migration?

A website migration is a broad term that encompasses any significant change to your website that affects how it’s structured, accessed, or presented. 

Website migrations come in many forms; anything from full domain changes, to content restructures. And, as such, the SEO implications vary significantly between the different types. 

What doesn’t change, however, is the thought and planning you should put into every migration. It may sound obvious, but SEO should be part of the conversation with any website migration. And it so often isn’t, even at enterprise-scale. Trust us; we’ve seen it firsthand.

 

💡 Further reading: Migrating from WordPress to Craft CMS: A Complete Guide

 

The Five Main Types of Website Migration, and Their Risks

To reiterate, the term 'website migration' encompasses a number of significant changes you might want to make to your website. However, there are a few that are that much more common than others.

Each type of website migration comes with its own risk/reward balance. And understanding exactly what you're aiming to undertake will give you a much clearer idea of the SEO risks involved and where best to concentrate your effort.

So, what are the different types of website migration? And what are the risks?

 

Migration Type	What it Covers	Primary Risk	Risk Level
Domain migration	Your root domain, or HTTP to HTTPS	Loss of link equity and trust signals	High
Platform / CMS migration	The underlying system, usually URL structure	URL changes without redirects; metadata and content loss	High
Structural redesign	Navigation, information architecture, URLs	Orphaned pages, broken internal links, diluted topical clusters	Medium–high
Content migration	Pages consolidated, merged, or removed	Losing pages that were ranking; thin replacements	Medium
Ecommerce replatform	Product URLs, category structure, faceted navigation	Everything above, plus index bloat and lost product-level rankings	Very high

 

Domain Migration

Over the years, your domain will have built its own "authority". Originally developed by SEO legends Moz, Domain Authority "predicts how likely a website is to rank on search engine results pages (SERPs) compared to competitors."

That means that moving to a new domain - or making URL changes like switching from HTTP to HTTPS - is one of the higher-risk types of domain migration.

Links from other websites, the quality of those links, your ranking history, and trust signals with search engines like Google all impact that authority. Your aim when you migrate is to preserve as much of that authority in the new domain as possible.

 

Platform or CMS Migration

Migrating from a legacy platform to something more modern, or switching CMS - from WordPress to Craft CMS, say, or a monolith to a headless setup - is a big change. And, consequently, there are a lot of things that can go wrong from an SEO perspective. 

One of the most common is changes to URL structure. If those changes go ahead without 301 redirects in place to map from old to new, you're going to lose link equity and, ultimately, rankings and traffic. This is probably the single biggest reason websites underperform post-migration. 

Of course, there are other elements that replatforming can affect; page speed, crawlability, and content/metadata loss can all be greatly impacted. There's a lot to consider. 

 

Structural Redesign

Even if you're not planning to migrate your domain or replatform, a significant restructure of your site's navigation or URL structure should be treated with the same importance. 

When you're moving pages, changing URLs (that will need redirecting), and consolidating content, it's so easy for things to be misplaced or not updated. You need to be thorough; all of these changes have SEO implications you should be wise to.

💡 Further reading: Website Redesign: 10 Signs it's Time (And How to Get it Right)

 

Content Migration

Similarly to above, content migration is something to treat with respect. As you would expect, these typically bring lower risk with them than a full platform or CMS switch, but a full and considered plan is still advised. 

Content consolidation, page removals, and merging sections of your website can all have an impact, especially if you're making changes to pages that rank well. 

 

eCommerce Replatform

With an eCommerce replatform, all of the above applies, and potentially becomes even more complex. Product and category URLs (sometimes running into the thousands, or more) multiply the difficulties of mapping, faceted navigation (otherwise known as product filtering) can create crawl traps, and out-of-stock or discontinued products need a redirect approach all of their own. 

In other words, eCommerce replatforms can be the most time-consuming migrations of all. In fact, they usually are.

 

Why Migrate Your Website?

As you can see, there are any number of reasons why you might need to undertake a website migration. None of them should be taken lightly. 

At the end of the day, all migrations are driven by a business need:
 

• Moving to a new domain
• A CMS that no longer suits your needs
• Performance issues
• Business ambitions that require scale
   

None of those is a bad reason to migrate. The point isn't to avoid migrations; it's to do them properly. Because, handled well, a migration shouldn't just protect your existing rankings. In the longer term, it should set you up to improve on them.

 

Why Do Website Migrations Impact SEO?

Google - other search engines are available - spends a lot of time getting to know your website. How it performs, what content you’ve got, and how good that content is; everything it needs to know to rank your website. Migrations tend to disrupt that process.

 

Changes to URLs

One of the commonest disruptors to that process is changes to URLs. 

If a page that previously lived at /services/web-design has moved to /services/website-design, it's feasible that search engines could lose track of it, or not pass the equity from old to new. 

It's in your best interests to make Google's job as easy as possible. And without the correct redirects in place, there's a chance the ranking history and authority attached to that URL evaporate. 

 

Broken Backlinks

Backlinks are one of the most valuable signals in SEO. Simply put, these are incoming links from other websites that point to your website. They are considered important because saying “look at me, I’m great”, they say “look at that guy, he’s great” - a far more compelling recommendation for Google to take notice of. 

The issue comes when those backlinks start returning a 404 error because your URLs have changed. You've effectively lost all that value. And unlike a rankings dip, broken backlinks don't automatically recover.

 

Content Changes

Much the same is true of sweeping content changes. With the best will in the world, getting a new site live is often a rush and content can get rewritten, shortened, or even lost in the process. 

The issue comes when a page that ranked well for a particular search term is changed significantly and for the worse. Those changes can impact organic rankings quickly and without warning. 

 

Technical Issues

There's a lot more to the technical side of SEO than URLs and redirects. And these technical issues on your new platform or CMS implementation can so easily compound. 

Underwhelming page speed, crawl errors, and broken internal links often go hand-in-hand. And together they can make the job of search engines more difficult than it needs to be.

To add to that, many of these technical considerations are direct ranking factors themselves. You need to make sure that your new website doesn't just look the part. It also needs to be slick, lightning fast, and optimised with crawlers, LLMs and humans in mind. 

💡 Further reading: What is Technical SEO? The Basics for Website Audits

 

Example Site Migration Timeline

A lot of the site migration advice out there will tell you what to do, but not when to do it. In our opinion, this is half the battle. As Russ points out above, timing is often where site migration projects come unstuck. 

Below is a typical schedule that we will work to when leading on a site migration. Of course, every project is different; this is just representative. You can adjust the expected delivery times up for more complex projects (especially ecommerce). 

 

Phase	Timing	Deliverable
Benchmark	T-8 weeks	Crawl, record baseline performance, identify priority pages
Map	T-6 weeks	Build the URL mapping document; agree the redirect policy
Build & block	T-6 to T-1 weeks	Staging environment blocked from crawlers; metadata and schema built in
Test	T-1 week	Redirect logic tested in full; crawl the staging site as though it were live
Launch	Day 0	Redirects live, robots.txt corrected, sitemap submitted
Verify	T+24 hours	Full crawl, Search Console check, spot-check priority URLs manually
Monitor	T+1 to T+4 weeks	Daily Search Console; weekly rankings and traffic
Assess	T+90 days	Compare against baseline; decide whether recovery is on track

 

SEO Migration Checklist

It should now be clear that having a structured and thorough plan in place is absolutely essential for any website migration. Not only does having all bases covered reduce any SEO risks, but it also speeds up recovery (because your rankings will be impacted, if only a little). 

It goes without saying that every migration is different, but the steps below cover the core of protecting your rankings.

 

Before Migration

Action
Crawl your existing site and export all indexable URLs
Benchmark current rankings, organic traffic, and indexed pages
Identify your highest-value pages (traffic, backlinks, conversions)
Audit your backlink profile to identify the most valuable pages
Create a full URL mapping spreadsheet (old URLs → new URLs)
Back up your site files, database, and existing sitemap
Ensure all key content, metadata, canonicals, and structured data will migrate intact
Confirm robots.txt rules and indexing settings for launch
Agree on a clear go-live timeline with developers and other stakeholders
Verify access to Google Search Console and analytics platforms (GA4)

 

During Migration
 

Action
Block search engines from crawling the staging environment
Implement 301 redirects for every changed or removed URL
Update internal links to point directly to new URLs (avoid redirect loops)
Check titles, meta descriptions, canonicals, and schema have migrated correctly
Test page speed, Core Web Vitals, and mobile performance on the new platform
Confirm the new site is running on HTTPS
Thoroughly test redirect logic before you launch

 

After Migration
 

Action
Submit your updated XML sitemap in Google Search Console
Crawl the new site immediately and resolve any errors
Cross-check live URLs against your pre-migration crawl
Monitor Google Search Console closely for crawl errors and indexing changes
Track rankings and organic traffic weekly for the first three months
Identify high-value backlinks still pointing to old URLs and update
Monitor indexation to ensure key pages are being discovered

 

Before You Migrate: The Groundwork

Doing the proper groundwork before a migration is where many projects stumble. And it’s difficult. SEO is often an afterthought for teams that are too busy or don’t necessarily have the right in-house expertise.

 

Crawl & Benchmark

You can’t measure the impact of anything without a benchmark. That means crawling your existing site - we recommend Screaming Frog - to capture every live URL. You’ll also want to keep track of current rankings and performance levels. 

 

Map your URLs

Many migrations involve URL changes. Assuming that’s the case, you’ll want to map every URL in a spreadsheet before anything changes. Trust us, it’s easier this way. 

Don’t over-complicate it. Put every current URL on the left and its new destination on the right. Every URL that changes needs a new destination. If you’re removing a page, redirect it to the closest equivalent. Try to avoid sending everything to your homepage. 

 

Audit Your Backlink Profile

Those of you who are serious about SEO will already have a tool like Ahrefs or SEMrush. And if you don't, they're not that expensive for individual businesses, and getting to grips with one or the other is an invaluable tool in your arsenal. 

Use either of these to export your existing backlink profile. Identify the pages that have the most valuable external links pointing to them.

This process helps you identify the highest-priority pages when it comes to redirection. You absolutely don’t want these pointing to a 404. Give them some extra love. 

 

During the Migration: Getting it Right

Hopefully, you’ve absolutely nailed the groundwork by this point, and the plan is solid. Now it’s over to your development team. But there are a few key points to consider.

 

Block Search Engines from Staging

Your staging site should be invisible to search engines. If Google ends up crawling your staging site, it’s possible you’ll end up with duplicate content issues. 

The minimum requirement is a robots.txt disallow. But you can also add password protection for extra safety. If you make sure your solution is in place from the start, there’ll be no issue.

 

Implement 301 Redirects

This is the big one. Remember that mapping document you made? Well, it’s about to come in handy. A 301 redirect tells search engines that a page has permanently moved to a new location. It passes the majority of the ranking authority from the old URL to the new one.

Keep an eye out for redirect chains - where one URL redirects to another, which redirects to another, etc… - which should be avoided. Redirect loops, where two pages redirect to each other, will break the page entirely. Test before launch. 

 

Verify Your Metadata

Before migration is complete, every page on the new site should have its title tag, meta description, and canonical tag intact.

It's surprisingly common for metadata to get dropped or defaulted during a platform migration. Different platforms handle metadata differently; there’s no guarantee everything will carry over automatically.

 

After the Migration: Monitoring & Recovery

Don’t forget about all of this once your site is live. There are still a few crucial bits and pieces to get done. And, no doubt, you’ll pick up a few things you missed the first time round. 

 

Submit Your Sitemap

The first thing to do after migration is to submit an updated XML sitemap to Google Search Console (GSC). This tells Google something has changed and gives it a clear map of what needs to be indexed.

And GSC isn’t a one-and-done either. It’s actually a very useful website management tool that you should check in with regularly. 

In fact, it’s worth checking daily, especially in the first few weeks after launch. For overall performance, but also for crawl errors, indexing issues, or any sudden changes. If something dramatic has gone wrong, it should be obvious in GSC.

 

Crawl Your Site

Don’t wait for Google to crawl your website and find errors. Do it yourself. You can use tools like Screaming Frog - an SEO favourite - to catch any erroneous 404 errors, broken links, or missing metadata. 

Cross-reference your post-launch crawl against your pre-migration URL list. Everything that should be live should be live. Everything that's moved should have a redirect in place.

 

How to Prioritise Your URLs During Migration

Not every URL on your website warrants equal attention. Giving every single page your undivided attention, especially in complex projects, just slows the whole process down unnecessarily.

We’re not suggesting you compromise on quality, but you want to be in a position to give extra special attention to your most valuable pages.

The way to start this process is to score every one of your URLs against four criteria: ​

1. Organic traffic—sessions over the last twelve months (to account for seasonality).
2. Referring domains—how many external sites link to this URL? Are they good quality?
3. Conversions—enquiries, sales, downloads. High value pages don’t always see high traffic volumes.
4. Ranking positions held—pages sitting at positions four to ten are potentially fragile and must be handled with care.

 

Using these four categories, rank the results and split them into three priority groups. The most important get hand-checked because you can’t afford to damage them. Your middle tier gets pattern-based rules with sampled verification. Everything else gets pattern rules and an automated crawl.

 

Site Migrations and AI Search

Three years ago, AI search wouldn’t have been on anyone’s list of considerations for site migrations. But such is the pace of change…

Large language models (LLMs) cite sources by URL. When ChatGPT, Perplexity, Google's AI Overviews or Claude reference your content, they link to a specific page. If you change that URL without a redirect (or get it wrong), you now lose both the Google ranking and a high-value citation.

​The recovery timeline looks different for AI search, too. Traditional organic rankings recover, by and large, as Google recrawls. But AI citations rely on retrieval systems and training data that don’t refresh at the same interval.

In other words, a broken URL in an AI-cited context can persist a lot longer than a broken URL in Google's index. This means:​

1. Redirects matter more than they used to. The argument for tidying up "messy" legacy URLs by simply removing them is significantly weaker.
2. Structured data needs to survive migration. If your schema markup doesn't migrate, you lose the machine-readable context that helps AI systems understand and correctly attribute your content.
3. Content consolidation carries a hidden cost. Merging three decent pages into one excellent page is often the right SEO call, but you're now also collapsing three potential citation targets into one.

​

💡 Further reading: Schema Markup: What it Does, What it Doesn’t, and Why it Still Matters

 

How Long Does SEO Recovery Take After Migration?

How long is a piece of string? The only honest answer here is: it depends.

For a well-planned, managed, and executed migration - redirects are done properly, content is preserved, and technical issues are mitigated - the impact should be minimal. Recovery often begins within weeks, but full stabilisation can take several months, especially for large or complex sites.

For a poorly managed migration where SEO simply hasn’t been considered and there’s no real plan in place, recovery can take months. Or years. Or never happen. In the worst cases, where content has been lost, backlinks have all broken, and redirects haven’t been put in place, rankings may never recover. 

 

 

It’s worth knowing that none of this is immediate. Google won’t process your migration all at once. It will recrawl and reassess your site over time, which is why recovery tends to be gradual (even after a great migration), rather than an overnight miracle. Be patient.

As we said at the very top, it’s pretty much impossible for a migration to have no negative impact on search rankings. Disruption is inevitable. And you will find things you missed. Your objective is to minimise the dip when it happens and to hasten recovery.

 

When to Worry

As we've said throughout this guide, some volatility post-migration is normal and expected. You've likely just made a big change to your website; disruption is inevitable.

But recovery won't always be the case, especially if you haven't given your migration enough care and attention. These are the signals that everything is not OK:

• Indexed pages dropping by more than a third and not recovering after four weeks
• Priority URLs returning 404s or landing on the homepage
• Crawl errors climbing rather than falling in weeks two and three
• Traffic still below 70% of baseline at the ninety-day mark

If you're seeing any of the above, it's time to start diagnosing the issues you're seeing.

 

Should You Migrate Your Website Yourself?

Technically speaking, with enough research, learning and time, you absolutely can handle most migrations yourself. But there’s potentially a lot of complexity involved, and there’s even more at stake if it goes wrong.

The main challenge is that there’s a lot going on and there are a lot of moving parts involved. Our usual recommendation is to work with a partner if possible. You may have the expertise in-house, but it’s definitely worth the investment of working with someone who has done it all before.

Just remember that the cost of a migration going wrong will almost always exceed the cost of getting it right the first time.

This is something we’ve done many times over the years, and we have specific expertise when it comes to migrations involving Craft CMS. So, if you do want to explore migrations but need some support, just reach out.