Definition
A site migration is any major change to a website's platform, domain, URL structure or design that can affect how search engines crawl, index and rank it.
Site migration explained
Migrations include moving to a new CMS or e-commerce platform, changing domain, switching to HTTPS, merging sites, restructuring URLs and redesigning templates. Each can change hundreds or thousands of URLs, templates and internal links at once, which is why migrations are one of the riskiest moments in a site's SEO life.
A careful migration follows a sequence:
- Benchmark current rankings, traffic and conversions by page.
- Build a redirect map from every valuable old URL to its new equivalent.
- Test the new site on staging: content parity, metadata, structured data, internal links, speed and redirects.
- Launch at a quiet time, then crawl old URLs, submit new sitemaps and monitor Search Console daily.
Google's site move documentation expects some fluctuation while it recrawls and reprocesses a moved site. Planning, testing and fast fixes after launch keep that period short, and preserve the SEO value the site has built.
Example
Your company is rebranding and moving from oldbrand.com to newbrand.com. Mapping every URL, redirecting each one to its new equivalent, testing on staging and using Search Console's change of address tool after launch is a site migration done with SEO preserved.
Why it matters
A well-run migration keeps years of rankings and links intact. A rushed one can cost months of traffic.
Related service
Website Migration
Platform, domain and redesign migrations planned URL by URL, tested on staging before launch.
Website migration with full SEO preservationSources
- Google Search Central: Site moves with URL changes (updated 20 Aug 2026)
Published by Vidern, founded and led by Malhar Shah. Updated .
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Related terms
- Redirect mapA redirect map is a spreadsheet pairing every old URL on a site with the new URL it should permanently redirect to, used to plan migrations.
- Staging environmentA staging environment is a private copy of a website where changes are built and tested before they go live on the production site.
- 301 redirectA 301 redirect is a permanent redirect: the server tells browsers and search engines that a URL has moved for good and sends them to the new address.
- Canonical tagA canonical tag is an HTML link element that tells search engines which URL is the preferred version of a page when similar or duplicate versions exist.
- Orphan pageAn orphan page is a page no other page on your site links to, so crawlers and visitors can only reach it via a sitemap, external link or direct URL.