A site migration is any significant change to a website’s location, structure, platform, or design that can affect how search engines find and rank its pages. Moving to a new domain, switching content management systems, redesigning the URL structure, or changing from HTTP to HTTPS all count. An SEO company handles a migration as a controlled, step-by-step process built to carry rankings and traffic across to the new site rather than lose them. Here is how that process usually works.
Pre-migration planning and URL inventory
The first step is a full inventory of the current site. The SEO company crawls every page with a tool such as Screaming Frog and pulls a complete list of URLs, including pages, images, PDFs, and any URLs that receive search traffic. They cross-check this against analytics and Search Console data so that nothing with rankings, traffic, or backlinks is missed. They also record a performance baseline: current rankings for important keywords, organic traffic by page, indexed page count, and top landing pages. This baseline is the reference point for judging whether the migration succeeded. A technical audit at this stage catches existing problems so they can be fixed before the move rather than carried into the new site.
Mapping one-to-one redirects
Every old URL needs a destination on the new site. The SEO company builds a redirect map that pairs each old URL with the single most relevant new URL, ideally a one-to-one match. These are implemented as 301 redirects, which tell search engines the move is permanent and pass ranking signals to the new address. Server-side 301 redirects are used because they are faster and more reliable than JavaScript or meta-refresh redirects. The team avoids redirect chains, where one URL points to another that points to a third, since these slow crawling and weaken the signal. When a page has no direct equivalent, it is redirected to the closest related page rather than dumped on the homepage.
Preserving metadata and content
The SEO company makes sure page content, titles, meta descriptions, headings, structured data, and image attributes transfer to the new site. Canonical tags, hreflang tags where used, and internal links are reviewed so they point to the correct new URLs. If the migration includes a redesign, the team checks that important on-page content is not cut or buried during the rebuild, since thinner pages can lose rankings.
Staging review
Before launch, the new site is built and tested in a staging environment, a private copy of the site that search engines and the public cannot see. The SEO company crawls staging to confirm redirects resolve correctly, metadata is in place, the XML sitemap lists only canonical and indexable URLs, and there are no broken links or unintended noindex tags. This is where problems are caught while they are still cheap to fix.
Launch-day checks
On launch day the team removes the restrictions that kept staging private: robots.txt disallows, noindex tags, and any password protection. They confirm DNS records point to the right server and that the server can handle the temporary spike in crawl activity that follows a migration. They verify that 301 redirects are live and returning the expected status codes, submit the new XML sitemap in Google Search Console and Bing Webmaster Tools, and, for a domain change, use Google’s Change of Address tool to notify search engines directly.
Post-launch monitoring and fixing issues
After launch the SEO company watches the site closely. They track indexation, crawl errors, rankings, organic traffic, and Core Web Vitals, comparing results against the pre-migration baseline. The first weeks call for frequent checks, often daily, then weekly as the site stabilizes, with monitoring continuing for several months on larger migrations. Common issues such as missed redirects, 404 errors, broken internal links, or pages dropping out of the index are fixed quickly, because speed of response limits how much traffic is lost. A short, temporary dip in indexed pages and rankings is normal after a migration; the goal is a steady recovery, and prompt fixes are what make that recovery happen.