SEO Migration

Why it matters

An SEO migration can disrupt rankings, indexing, internal linking, and crawl paths. The primary goal is to minimise traffic loss while transferring relevance and authority to the new version. Google recommends preparing the new site thoroughly, creating a URL mapping from old to new URLs, and then redirecting old URLs to the new ones using 301 redirects. These redirects preserve the path for users and help transfer signals. After launch, Google advises submitting the new sitemap in Search Console and removing the old one. Testing redirects before and after launch is critical; Google suggests using the URL Inspection Tool or command-line scripts for large sets. Preserving content, metadata, schema, and internal links helps maintain relevance and reduce ranking volatility. The impact of redirects, canonicals, and internal linking can vary as Google recrawls and reprocesses signals, so ongoing monitoring remains essential. Factors such as crawl budget can be affected by unnecessary redirect chains, so careful mapping is vital.

Detailed monitoring seo performance after launch should focus on crawl errors, indexation changes, ranking shifts, traffic drops, and redirect problems. Google recommends keeping redirects in place for at least one year, because external links and bookmarks take time to update. A full migration plan usually includes auditing the current site, benchmarking traffic and rankings, and identifying high-value pages before launch. Post-launch, allow time for Google to recrawl and reassign signals; ranking recovery is not instant.

Where it changes your decision

• Moving to a new domain: all URLs change, so 301 redirects are essential to preserve traffic and ranking signals. Without proper mapping, the new domain may not inherit the old domain's authority.
• Changing URL structure on the same domain: restructuring paths can break internal links, bookmarks, and cached pages. URL mapping and redirects are needed to avoid 404 errors and loss of link equity.
• Migrating to a new CMS or platform: platform changes may alter URL patterns, canonical tags, and metadata. Ensuring the new system generates correct canonical tags and sitemaps is critical to maintain indexation.

What it is not

• It is not just a redesign. A redesign may change the look and feel but not URLs; an SEO migration involves URL changes and requires redirects.
• It is not simply a content migration. Content migration focuses on moving content from one system to another, but may not preserve SEO signals like link equity, robots.txt, or canonical tags.
• It is not the same as a domain redirect. A domain redirect is a single redirect; a full migration includes updating all internal links, sitemaps, canonicals, and monitoring.
• It is not a one-time event. Post-launch monitoring is required because search engines may take weeks or months to fully recrawl and reassign signals.

Common mistakes

• Using temporary redirects (302) instead of 301: search engines may not transfer ranking signals, causing traffic loss and ranking drops.
• Blocking the new site with noindex, password protection, or staging rules after launch: prevents search engines from indexing the new site, leading to disappearance from search results. Also check that robots.txt does not block crawlers, as this can create crawlability issues.
• Forgetting to update canonicals, internal links, or XML sitemaps: creates duplicate content issues and confuses search engines about the canonical version of each page.
• Deleting redirect rules too early: external links, bookmarks, and cached pages may still point to old URLs, resulting in 404 errors and lost traffic. Google recommends keeping redirects for at least one year.
• Not testing redirects before launch: broken redirects can cause a cascade of errors. Testing both the old-to-new path and the final URL is essential.