A migration is more than putting a new design online

A website migration may involve a new CMS, different hosting, a changed URL structure, a new domain or several of these at once. Not every move changes what visitors see, but every change can affect what search engines are able to crawl, understand and retrieve.

Website migration SEO therefore starts well before launch. The aim is not to rule out every fluctuation — Google describes temporary changes in crawling and visibility as normal — but to move valuable pages in a recognisable way and expose mistakes quickly. These ten checks give marketing, content and development one practical playbook.

1. Define exactly what is changing

Document whether you are changing hosting only, updating URLs, moving to another domain, rewriting content or replacing the design and platform together. The scope determines the right checks. A hosting move without new URLs needs different preparation from a domain migration with an entirely new site structure.

Assign owners for URL mapping, redirects, metadata, analytics, Search Console, DNS and the final go or no-go decision. When everything changes without clear ownership, a later decline is difficult to explain. Create a timeline that includes testing, launch and reviews during the following days and weeks.

2. Build an inventory of the current website

Collect existing URLs from the XML sitemap, CMS and a crawl of the website. Add organic landing pages from Search Console, visited pages from analytics and important URLs that attract links from other websites. This helps find pages that may not appear in the main navigation.

Record each URL's status, title, canonical, indexability, organic purpose and intended action: keep, merge, replace or deliberately remove. Save a pre-migration baseline for relevant queries, landing pages, conversions and technical errors too. That context makes post-launch monitoring much more useful.

3. Map every old URL to a relevant destination

Create a URL map in which every old indexable page has a clear new destination. If the content remains, map it directly to the most comparable new page. If several pages are genuinely consolidated, one complete new page can replace those older variants.

Do not send every removed page to the homepage. Google warns that large numbers of irrelevant redirects may be treated as soft 404s. If an old page has no suitable alternative, a clear 404 or 410 can be more honest than a misleading redirect. Make that decision page by page and from the visitor's intent.

4. Keep the staging environment out of search results

Protect a staging website with authentication or another real access restriction where possible. If you temporarily use noindex, make sure crawlers may still access the page to read that instruction. A robots.txt block alone does not guarantee that a URL will never appear in search results.

Make removing temporary blocks part of the launch checklist. Review robots.txt, meta robots, X-Robots-Tag and platform settings across representative pages. A perfectly built website remains invisible when production accidentally inherits noindex from staging.

5. Carry important content and signals across deliberately

Compare old and new versions by page type: title, main heading, core copy, internal links, images, alt text, structured data and essential product or service information. A URL can move correctly at a technical level while losing much of the content that made it relevant.

Review canonicals and, for multilingual websites, hreflang. After launch, these references must point to the final new URLs. Update navigation, breadcrumbs and links inside articles as well; internal links that pass through a redirect create an unnecessarily indirect experience for visitors and crawlers.

6. Use permanent redirects without detours

When a URL moves permanently, Google recommends a permanent server-side redirect where possible, such as 301 or 308. Test that each old URL reaches the intended new URL directly, returns the correct status code and creates no loop.

Avoid chains such as old to interim to new. Google can follow redirects, but a direct route is faster and easier to maintain. Update existing rules when a page has moved before. Test more than the homepage: sample categories, products, services, articles, images and language versions where relevant.

7. Test production as a complete customer journey

Before and immediately after launch, review status codes, canonicals, indexability, structured data, mobile layouts, forms, site search, filters and checkout. Inspect the source or rendered HTML for key templates and confirm that titles and meta descriptions are generated correctly.

Follow measurement from start to finish too. Test GA4 events, conversions, consent, campaign parameters and advertising pixels on the new domain or platform. Annotate the migration date in reporting. This helps distinguish a real behaviour change from missing tracking or a shift in organic traffic.

8. Publish a clean sitemap and use Search Console selectively

Include only final, canonical URLs that return status 200 and are eligible for indexing in the new XML sitemap. Reference it in robots.txt and submit it in Search Console. Google describes a sitemap as an important discovery method after a new launch or recent site move.

Inspect a small set of priority pages with URL Inspection and request indexing only where useful; repeated submissions do not speed up crawling. When the domain or subdomain changes, use Change of Address for the verified old property. The tool is not needed for http-to-https moves, switching between www and non-www, or path changes within the same domain.

9. Monitor both old and new URLs

After launch, follow Page Indexing reports, sitemaps, crawl activity and selected canonicals in Search Console. Review important queries and organic landing pages as well. In analytics, examine both traffic and outcomes: enquiries, purchases, subscriptions or the actions that matter to the business.

Compare error logs and a crawl of the old URL inventory with the new site. Look for unexpected 404s, redirect chains, incorrect canonicals, blocked pages and internal links to old addresses. Fix patterns first; one template error can affect hundreds of URLs and deserves more attention than an isolated missing page.

10. Keep redirects and old ownership active long enough

Do not remove redirects as soon as traffic seems stable. For moves involving URL changes, Google generally recommends keeping redirects for at least one year. Longer can help people who continue to use old bookmarks, emails or external links. When the domain changes, retain the old domain and technical control of it.

Update your own channels at the same time: important external profiles, advertising links, email templates, downloadable documents and high-traffic references. Every old link does not need to change immediately, but updating the main direct routes reduces reliance on redirects and keeps the brand experience consistent.

A strong migration exposes risks before they become problems

The safest order is practical: inventory first, then URL mapping, content and signal testing, redirect activation, complete journey checks and structured monitoring. Launch only after critical blockers are resolved and the owner of post-launch anomalies is clear.

SEO cannot make a migration risk-free and nobody can guarantee rankings. What you can do is make every important choice traceable. A website refresh then becomes a controlled transition in which technology, content, data and brand all move in the same direction.

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