SEO site migration: How to move your website without losing traffic

Site migrations have a bit of a reputation in SEO.

Traffic drops. Rankings disappear. Panic sets in…

And to be fair, that does happen. Usually when migrations are rushed, poorly planned, or treated as just a dev project rather than an SEO-critical moment. But when they’re done properly, they don’t just protect performance, they can actually improve it.

At TAL, we’ve supported a number of migrations where the goal wasn’t just to “not lose traffic”, but to come out stronger. The key is knowing what matters, where the risks are, and how to manage them properly.

What is an SEO site migration?

A site migration is any significant change that affects your website’s structure, content, or URLs.

That could be:

• Moving to a new domain
• Changing CMS
• Restructuring URLs
• Redesigning the site
• Consolidating or removing pages

From an SEO perspective, all of these impact how search engines understand your site.

If handled badly, you lose visibility. If handled well, you maintain equity and set yourself up for growth.

Why migrations go wrong

Most migrations fail for the same reasons.

SEO is brought in too late. Redirects are rushed. Content gets lost. Structure changes without thinking about search.

The biggest issue is that Google relies heavily on consistency. When you change URLs, content, and structure all at once without clear signals, it has to reprocess everything.

That’s where drops happen.

What actually protects your rankings during a migration

There isn’t one magic fix. It’s a combination of things done properly.

1. URL mapping and redirects done properly

This is the foundation. Every existing URL needs to be mapped to the most relevant new version. Not just bulk redirected, but matched based on intent. If you get this wrong, you lose link equity, rankings, and traffic.

2. Maintaining site structure and key themes

Google doesn’t just rank pages, it understands structure.

If your site currently ranks well for key themes, those need to be preserved. Removing or diluting them can have a big impact. This is where migrations often fall down. Structure gets simplified for UX or dev reasons, but SEO value is lost in the process.

3. Content continuity and optimisation

Content shouldn’t just be migrated. It should be reviewed.

This is an opportunity to:

• Strengthen key pages
• Improve relevance
• Fill gaps

Done well, this is where you move from “protecting traffic” to actually growing it.

4. Technical SEO foundations

Things like crawlability, indexing, page speed, and structured data all matter. If your new site is harder to crawl or slower to load, it will impact performance. If it’s cleaner and better structured, it can improve it.

Case study: ASDA Photo migration

A good example of this in practice is our work with ASDA Photo.

They were migrating their photo services platform to a new domain and CMS. The priority was clear. Protect existing performance while setting the site up for future growth.

This wasn’t just a lift-and-shift. It needed to maintain visibility across highly competitive photo print and gifting terms.

What we focused on

We started with detailed site structure mapping to make sure key themes remained visible and accessible post-migration.

From there, we built out comprehensive redirect mapping to preserve SEO equity and minimise risk. Every important URL had a clear destination, aligned to user intent.

Alongside that, we strengthened content across key categories, particularly around photo prints and gifting, ensuring the new site wasn’t just equivalent, but better.

We also introduced structured data recommendations to support stronger visibility in search and future-proof the site for AI-driven features.

The result

The migration didn’t just maintain performance. It improved it. We saw a 58% uplift in page one keywords year on year. Position one rankings increased by 69%. And estimated organic traffic more than doubled, with a 105% uplift.

That’s what happens when a migration is treated as a growth opportunity, not just a risk to manage.

How to approach your own migration

If you’re planning a migration, the most important thing is timing and planning.

SEO needs to be involved early. Not after decisions have been made.

You need to understand:

• What currently drives traffic
• Which pages matter most
• Where your authority sits

From there, everything should be mapped, tested, and validated before launch. And once you go live, the work doesn’t stop. Monitoring, fixing issues, and refining the setup is just as important as the planning stage.

Migrations are an opportunity, not just a risk

It’s easy to see migrations as something to get through without damage.

But the reality is, they’re one of the few moments where you can make large-scale improvements to your site.

If you approach it properly, you don’t just protect your rankings. You put yourself in a stronger position than before.

Planning a site migration? Let’s make sure you get it right

Site migrations are high risk, but they’re also high opportunity.

At TAL, we support brands through migrations with a focus on protecting performance and unlocking growth. From mapping and redirects to content and technical SEO, we make sure nothing gets lost along the way.

If you’ve got a migration coming up and want to do it properly, we’d love to help.

Get in touch with the team and let’s make sure your migration works for you, not against you.

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