Website Migration SEO Checklist: How to Change Platform or Domain Without Losing Traffic

Migrations are where most sudden SEO traffic drops come from. This checklist covers planning, redirect mapping, launch day and post-launch monitoring for platform and domain changes.

Most dramatic organic traffic drops I am asked to investigate have the same cause: a website migration. A new platform, a new domain, a new URL structure, or a redesign that quietly changed hundreds of URLs.

The good news: migrations do not have to cost traffic. With proper planning, most sites keep their rankings, and some improve. This checklist covers what to do before, during and after.

Types of migrations

  • Platform migration: for example WooCommerce to Shopify, Magento 1 to Magento 2, Magento to Shopify
  • Domain migration: new brand or domain name
  • Protocol / subdomain change: HTTP to HTTPS, non-www to www
  • URL structure change: new category structure or removed .html suffixes
  • Redesign / content migration: new templates, merged or removed pages

Each one carries risk. A combination (new platform + new domain + new URLs at once) carries the most.

Phase 1: Planning

1. Set goals and a launch date

Avoid launching right before your peak season. Plan for a few weeks of extra attention after launch.

2. Benchmark everything

Save before the migration:

  • Organic traffic and conversions per landing page (analytics)
  • Clicks, impressions and positions per page and query (Search Console exports)
  • Top-ranking keywords
  • Pages with the most backlinks

3. Crawl the old site completely

Use a crawler to get every URL: pages, products, categories, images, PDFs. Combine it with URLs from Search Console, analytics, sitemaps and backlink tools. A crawl alone misses orphaned pages that still get traffic.

Phase 2: Redirect mapping

4. Map every old URL to the best new URL

Create a spreadsheet: old URL → new URL. Rules:

  • Redirect to the most relevant equivalent page, not the homepage
  • Use 301 (permanent) redirects
  • Avoid redirect chains (old → intermediate → new); redirect directly to the final URL
  • Removed products with no equivalent → closest category

5. Do not forget

  • Old redirects from earlier migrations (update them to point to the new final URL)
  • Image URLs that rank in image search
  • PDF and download URLs with backlinks
  • Parameter URLs that receive traffic
  • Language and country versions

6. Decide where redirects live

Platform redirect manager, web server configuration or CDN rules. Very large redirect lists are often better handled with pattern rules at server or CDN level.

Phase 3: Pre-launch checks on staging

7. Block staging from search engines

Use password protection. Do not rely only on noindex, which is easy to forget to remove at launch.

8. Compare old and new pages

For your most important templates and top 100 URLs, check:

  • Title and meta description
  • H1 and main content
  • Canonical tag
  • Structured data
  • Internal links
  • hreflang

9. Test the redirect map

Crawl the list of old URLs against staging and check that every one returns a single 301 to a 200 page.

10. Check analytics and tracking

Make sure GA4, ads conversions and consent work on the new site before launch. Migrations often break tracking (see why GA4 conversions go missing).

Phase 4: Launch day

11. Go live and activate redirects at the same time

12. Remove staging blocks

Check robots.txt and noindex tags on the live site immediately.

13. Submit new sitemaps

Submit the new XML sitemap in Search Console. For domain migrations, keep the old property verified and use the Change of Address tool.

14. Crawl the live site

Look for 404s, redirect chains, accidental noindex and broken canonical tags.

Phase 5: After launch

15. Monitor daily for the first weeks

  • 404 errors in Search Console and server logs
  • Indexing status of new URLs
  • Rankings and clicks for your top pages
  • Conversion rate and revenue

16. Fix 404s with traffic quickly

Add missing redirects as soon as you find them.

Social profiles, Google Business Profile, marketplaces, partner sites and your most valuable backlinks.

18. Keep redirects in place long term

Keep 301 redirects for at least a year, ideally permanently. Removing them later can lose the value of old backlinks.

What is normal after a migration?

Some fluctuation in the first weeks is normal while Google recrawls and processes redirects. A drop that continues or deepens after several weeks usually means missing redirects, content changes or technical problems on the new site.

Frequently asked questions

Will I lose traffic when I migrate my website?

Not necessarily. With a complete redirect map and preserved content, many sites see only short-term fluctuations.

How long does it take Google to process a migration?

Smaller sites can settle within a few weeks; larger sites can take months to be fully reprocessed.

Should I use 301 or 302 redirects?

301 for permanent moves. 302 is for temporary changes.

Can I change platform and domain at the same time?

You can, but it is riskier and harder to diagnose if something goes wrong. If possible, do one at a time.

Planning a migration?

I plan and support SEO-safe migrations between WooCommerce, Shopify and Magento, including redirect mapping and post-launch monitoring. See my technical SEO service or request migration support.