The Ultimate Website Migration SEO Checklist

Website migrations are among the highest-risk activities in SEO. Even well-planned migrations routinely result in traffic drops of 10-30% in the short term. Poorly executed ones can be catastrophic. This checklist covers every critical step to preserve your SEO equity through a migration.

Pre-Migration Phase

Content and URL Inventory

Before changing anything, document everything that exists. Crawl your current site to capture every URL, its traffic, rankings, and backlink profile. This inventory becomes your source of truth for the entire migration.

• Crawl the current site and export all URLs
• Pull 12 months of organic traffic data per URL from GA4
• Export search impressions and clicks per URL from GSC
• Document all URLs with external backlinks
• Identify your top 50 pages by traffic and top 50 by backlinks

Redirect Mapping

The redirect map is the single most important document in any migration. Every old URL needs a corresponding new URL. One-to-one redirects preserve the most equity.

• Create a complete old URL to new URL mapping spreadsheet
• Use 301 redirects (permanent) for all URL changes
• Avoid redirect chains — each old URL should point directly to its final destination
• Map orphaned pages to the most relevant existing page
• Test a sample of redirects in a staging environment

Technical Preparation

• Set up Google Search Console for the new domain or URL structure
• Verify analytics tracking on the new site
• Ensure XML sitemaps are ready for the new URL structure
• Test robots.txt on the new site to confirm no accidental blocking
• Benchmark current Core Web Vitals scores for comparison

Launch Day

Immediate Actions

• Deploy all 301 redirects simultaneously with the new site
• Submit the new XML sitemap to Google Search Console
• Request indexing for your most important pages
• Verify redirects are working with a spot check of 20-30 URLs
• Monitor server logs for 404 errors in real time

Verification

• Crawl the new site to confirm no broken internal links
• Verify all canonical tags point to the correct new URLs
• Confirm hreflang tags are updated for international sites
• Check that structured data is present and valid on key pages
• Test the site on mobile devices for rendering issues

Post-Migration Monitoring

Week 1

• Monitor Google Search Console for crawl errors daily
• Track indexing of new URLs via the Coverage report
• Fix any redirect errors or 404s immediately
• Compare daily traffic to the pre-migration baseline

Weeks 2-4

• Monitor keyword rankings for your top 100 terms
• Check for any unexpected deindexation
• Review server logs for crawler activity patterns
• Address any new Core Web Vitals issues

Months 2-3

• Compare monthly traffic to pre-migration levels
• Analyze which pages have recovered rankings and which have not
• Submit any remaining unindexed pages for crawling
• Remove the old site (or old URL paths) once redirects are confirmed working

When Things Go Wrong

Traffic drops during migration are normal. Drops of 10-20% that recover within four to six weeks are typical. If traffic drops exceed 30% or do not begin recovering within two weeks, investigate immediately.

Common culprits include broken redirects, accidental noindex tags, missing canonical tags, and server performance issues that slow crawling. A thorough post-migration crawl compared against your pre-migration inventory will surface most problems quickly.