A new website should be a step forward, not a step back. Many businesses have come to us at Trio after a fresh site launched by someone else, because their organic traffic and rankings have dropped. In nearly every case, the drop wasn’t caused by the new design or the platform itself. It was caused by avoidable SEO mistakes made during the migration.
Migrations are one of the riskiest things you can do to a website’s search visibility. Years of ranking history, backlink authority and technical signals can be lost on launch day if the move isn’t planned carefully.
This guide walks through the most common SEO migration mistakes, why they happen, and what to do instead. If you’re about to migrate, it’s a useful checklist of things to avoid. If you’ve already migrated and something feels off, it’s a good place to start diagnosing where things may have gone wrong.
What is a website migration?
In SEO terms, a migration refers to any major change that affects how search engines crawl, index or interpret a website.
The most common scenario we work with at Trio is a migration to WordPress where a business moves from a platform like Wix, Squarespace or a bespoke CMS onto a WordPress build. This usually involves a complete change in URL structure and template architecture, often accompanied by a website redesign.
Other common migration scenarios include:
- Domain changes: switching to a new domain name entirely
- URL structure changes: restructuring your URL hierarchy within the same CMS
- HTTPS migrations: moving from HTTP to HTTPS
- Merging multiple websites: consolidating separate sites into one
- Subdomain or subfolder restructuring: moving content between subdomains and subfolders
- Platform-to-platform moves: such as WordPress to Shopify for e-commerce, or vice versa
Each of these alters the signals search engines rely on to interpret a site’s authority and relevance. The technical SEO principles for protecting rankings remain the same regardless of which platform you’re moving to, WordPress, Shopify, or anything else. The difference is in the implementation.
Why migrations can cause ranking drops
Search engines build their understanding of a website over time. Rankings aren’t just about content; they’re influenced by a combination of signals, including page authority, backlinks, internal linking, content relevance and technical structure.
When you move from one CMS to WordPress, several of these signals change at once. URL structures are almost always different. Internal linking often breaks because the old CMS generated links in a format WordPress doesn’t replicate. Page templates change, which can alter heading structures and content layout. And if a redesign happens at the same time (which it usually does), content itself may be rewritten or restructured.
If search engines can’t clearly connect the old URLs with the new WordPress URLs, ranking signals may not transfer correctly.
This can lead to:
- Ranking drops across key pages
- Lost backlink authority when external links point to old CMS URLs that no longer exist
- Indexing issues as Google tries to figure out the new WordPress structure
- Reduced organic traffic, sometimes dramatically
The goal of SEO during a migration is simple: keep those signals so search engines clearly understand how the old website connects to the new one.
Why do most migration issues start before launch?
One of the most common migration issues we see at Trio is when redesign projects focus purely on visual improvements without considering existing SEO performance.
Pages that generate strong organic traffic are sometimes removed, merged or heavily rewritten during the redesign process. When this happens, search engines lose the historical signals associated with those pages, which can result in ranking loss even if redirects are implemented correctly.
With years of experience working on website migrations, one consistent pattern stands out: most ranking losses are caused not by the migration itself, but by changes made during redesigns. When page structure, internal linking and content all change at once, search engines struggle to recognise that the page is the same entity as before.
This is why SEO planning should always begin before website development starts. Not after.
Common SEO migration mistakes (from real projects)
After working on website migrations for years now, the most common issues we see at Trio include:
Redirect chains
Multiple redirects between old CMS URLs and new WordPress URLs slow down crawling and dilute link equity. The old URL should always redirect directly to the final destination.
Pages removed during redesigns
Design-led migrations often remove older pages that still rank and drive traffic. Always check organic performance before removing any page from the new WordPress build.
Content changes during migration
Changing page content at the same time as URL structure makes it harder for search engines to transfer rankings. Change one thing at a time wherever possible.
Staging sites accidentally indexed
WordPress staging environments sometimes get indexed if the noindex setting or robots.txt isn’t configured correctly. This creates duplicate content issues that can take weeks to resolve.
Generic redirects
Redirecting every old CMS URL to the WordPress homepage instead of mapping to the correct page. Google treats this as a soft 404 and you’ll lose the ranking value of those pages.
WordPress “noindex” left on
The “Discourage search engines from indexing this site” checkbox in WordPress Settings > Reading is often ticked during development and forgotten at launch. One checkbox, massive consequences.The safest migration strategy is to change as little as possible at launch, then make improvements once rankings stabilise.
Worried about a migration? Let’s make sure nothing gets missed.
Most of these mistakes are easy to avoid when SEO is part of the migration plan from day one — and much harder to resolve once a site has already gone live. If you’re planning a move to WordPress, or you’ve recently launched and something doesn’t feel right, our team can help you spot the issues before they cost you rankings.
Speak to our team about your upcoming migration or review your recent launch with us.
FAQs
Will a website migration hurt my SEO?
It can, but it doesn’t have to. The migrations that cause lasting damage are the ones where SEO isn’t considered until after launch. When we manage migrations at Trio, we build the SEO strategy into the project from the start, auditing existing performance, mapping every URL, implementing redirects correctly and monitoring everything post-launch.
My website has already been migrated and my rankings have dropped. Can Trio help?
Absolutely. We’ve worked with businesses that came to us after a migration went wrong, sometimes months after launch. The process is similar to what we’d do pre-migration: we audit the current state, identify what’s broken (missing redirects, lost pages, crawl issues, content changes), and create a recovery plan. It takes longer than doing it right the first time, but rankings can usually be recovered. If you’re seeing drops after a recent migration, the sooner you act, the faster recovery tends to be.
Why should I use an SEO agency for a website migration instead of handling it in-house?
Having an agency like Trio involved means there’s someone whose entire focus is on protecting your search visibility throughout the project. We’ve handled migrations across WordPress, Shopify and custom CMS platforms, so we know where the common issues are and how to avoid them. We also bring technical depth that most in-house teams don’t have.
Is WordPress better for SEO than other CMS platforms?
WordPress gives you excellent SEO control out of the box: clean permalink structures, a massive plugin ecosystem for technical SEO and schema and the flexibility to structure content however you need. That said, any platform can perform well if it’s configured properly. The real advantage of WordPress is how much control it gives you over the signals that matter, which makes it easier for agencies like us to implement and manage your SEO strategy.
