TECHNICAL · SEO GLOSSARY
Site Migration
Moving a website to a new domain, URL structure, CMS, or HTTPS — one of the highest-risk SEO operations if not executed with a complete redirect map and pre/post-launch monitoring.
Definition
A site migration is any significant change to a website's URL structure, domain, CMS, hosting, or protocol that affects how search engines index and rank the site. Types: (1) **Domain migration** (`old-brand.com` → `new-brand.com`) — requires 301 redirects for every URL; (2) **URL restructure** (changing `/products/category/product` to `/p/product`) — requires a redirect map for all affected URLs; (3) **HTTPS migration** (http → https) — the simplest type, but incomplete redirect chains cause link equity loss; (4) **CMS migration** (WordPress → Headless) — content URLs often change; (5) **Platform migration** (Shopify → custom) — URL structure, canonical patterns, and sitemap format all change. Every migration has the same essential requirements: crawl the site before and after, map every old URL to its new equivalent, implement 301 redirects, update canonical tags and sitemaps, resubmit to Search Console, and monitor index coverage and traffic for 3–6 months post-launch.
Why it matters for SEO
Poorly executed site migrations cause some of the worst SEO disasters: a domain migration without proper redirects can cost 50–80% of organic traffic for 6–12 months. The most common failures: (1) breaking the redirect chain (old URL → new URL takes 3+ hops, diluting equity); (2) not redirecting all URLs (only redirecting the top 100 instead of all 50,000); (3) updating the sitemap before redirects are in place; (4) not monitoring GSC coverage errors in the weeks after launch; (5) moving from HTTP to HTTPS but leaving internal links, canonical tags, and the sitemap as HTTP URLs. A site migration should always have a rollback plan and should be launched with a pre-migration crawl snapshot for comparison.
How DeepSEOAnalysis checks this
The audit checks for migration indicators: redirect chains longer than 2 hops (flagged as equity-loss risks), broken internal links pointing to pre-redirect URLs, canonical tags with different domains or protocols from the current site, and sitemap URLs that don't match the canonical versions. If the site appears to have recently migrated (high rate of 301 redirects from internal links), the audit highlights this in the technical summary and recommends a full redirect chain audit.
Useful tools and resources
GLOSSARY
Related terms
technical
301 Redirect
A permanent HTTP redirect that passes ~90–99% of link equity from the old URL to the new one — the correct redirect type for permanent URL changes in SEO.
Read definition →technical
Redirect Chain
A series of redirects where URL A → URL B → URL C instead of directly to the final destination — wastes crawl budget and dilutes link equity.
Read definition →technical
Canonical URL
The preferred URL for a page, declared via <link rel="canonical"> to prevent duplicate content from splitting ranking signals.
Read definition →technical
HTTPS Migration
Moving a website from HTTP to HTTPS — a required step for Google's security ranking signal, user trust (the padlock), and accurate Core Web Vitals data.
Read definition →technical
Crawlability
Whether search engine crawlers can successfully access, fetch, and parse a page — the prerequisite for indexing and ranking.
Read definition →technical
Index Coverage
The count and status of pages Google has discovered, crawled, and indexed from a site — tracked in Google Search Console.
Read definition →See how your site scores on Site Migration.
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