TL;DR: Site migration (domain, platform, URL restructure) is high-risk. Follow systematic checklist to preserve SEO. Key: URL mapping, 301 redirects, testing before launch, monitoring after.
Types of Migration
- Domain change (example.com → newexample.com).
- Protocol (HTTP → HTTPS).
- Subdomain → subdirectory.
- Platform (WordPress → Shopify).
- URL restructure.
- CMS change with URL changes.
Pre-Migration (1-2 months before)
- Crawl old site (Screaming Frog). Export all URLs.
- Note all URLs with organic traffic (GSC).
- Note all URLs with backlinks (Ahrefs).
- Build URL map: old → new.
- Plan 301 redirects.
- Identify pages to preserve (high traffic/links).
During Migration
- Set up redirects before launch (301 Permanent).
- Test in staging.
- Update internal links to new URLs.
- Update canonical tags.
- Update sitemap.xml.
Launch Day
- DNS changes.
- Verify redirects work.
- Submit new sitemap to GSC.
- Monitor errors.
Post-Launch (1-4 weeks)
- Monitor GSC daily for errors.
- Check redirects working (spot check).
- Watch traffic trends.
- Fix issues quickly.
Common Mistakes
- Not setting up 301 redirects.
- Redirect chains (A → B → C).
- Changing too many things at once.
- Not monitoring post-launch.
Timeline Expectations
- Minor drop (5-15%) first month. normal.
- Recovery within 2-3 months.
- Significant drop (30%+) = problem. Diagnose.