Definition

A site migration is any change that affects how a site is reached or organised — a new domain, new URL structure, protocol switch from http to https, CMS replatform or large-scale information architecture change. Google has specific guidance for handling site moves with URL changes to limit traffic loss.

Google distinguishes site moves with URL changes — for example a domain change or restructure — from site moves without URL changes, such as a server move on the same hostname. URL-change migrations rely on 301 redirects from each old URL to its closest new equivalent, updated internal links, refreshed XML sitemaps containing the new URLs, and use of Search Console's change-of-address tool when the domain is changing. Migrations typically cause short-term ranking fluctuations while Google recrawls and reassigns signals from old URLs to new ones.

Examples

• Domain change with 1:1 redirects

  A brand moves from `oldbrand.com` to `newbrand.com`. Each old URL 301-redirects to the matching new URL, sitemaps are submitted for the new domain and Search Console's change-of-address tool is used to notify Google.

• Protocol switch to HTTPS

  A publisher migrates from http to https on the same hostname. Every http URL 301-redirects to its https equivalent, internal links are rewritten and the https property is added in Search Console.

Sources

• Google Search Central — Site moves with URL changes

Related terms

• 301 Redirect
  A permanent redirect — an HTTP 301 status code telling clients and search engines that a URL has moved permanently to a new location.
• HTTPS
  Hypertext Transfer Protocol Secure — the encrypted version of HTTP. Google uses HTTPS as a lightweight ranking signal.
• Sitemap
  A file, usually XML, that lists URLs on a site so search engines can discover and crawl them more efficiently.
• Redirect Chain
  A sequence of two or more redirects between an original URL and the final destination. Each hop adds latency and risk of signal loss.
• Indexing
  The process by which a search engine analyses a fetched page and stores information about it so the page can later be returned in search results.

Where QueryCatch uses this

• SEO Audit
• Sitemap Optimisation