Site Migration SEO Checklist Guide for SEO Teams

Why Site Migrations Are Risky for SEO

A site migration is any major change to your website’s URL structure, domain, platform, design, or content architecture. Every migration carries SEO risk because it changes signals that search engines have already indexed and evaluated.

The average site migration causes a 10-30% drop in organic traffic in the weeks following launch. Well-planned migrations recover within 2-4 weeks. Poorly planned migrations can take 6-12 months to recover — or never fully recover.

The difference is preparation.

Types of Site Migrations

Not all migrations carry the same risk level:

• Domain change (example.com to newexample.com) — Highest risk. All accumulated domain authority must transfer via redirects.
• Protocol change (HTTP to HTTPS) — Moderate risk. Google treats HTTP and HTTPS as separate properties.
• CMS change (WordPress to Shopify, custom to headless) — High risk. URL structures almost always change.
• URL restructure (changing URL patterns on the same domain) — Moderate to high risk. Depends on scope.
• Design/UX redesign (same URLs, new templates) — Lower risk. But content changes within templates can still impact rankings.
• Content consolidation (merging pages, removing thin content) — Moderate risk. Redirects must be precise.

Pre-Migration Phase

1. Benchmark Current Performance

Before changing anything, document your current state:

• Crawl your entire site — record every URL, status code, title tag, meta description, canonical tag, and internal link
• Export Google Search Console data — impressions, clicks, positions for all pages
• Record keyword rankings — track positions for your top 100-500 keywords
• Document indexation count — how many pages are currently indexed
• Capture backlink profile — which pages have external links pointing to them
• Save Google Analytics data — organic traffic by landing page for the past 12 months

This baseline is essential for measuring migration success and diagnosing post-migration issues.

2. Create a Complete URL Mapping

The URL map is the single most important document in a site migration. It maps every old URL to its corresponding new URL.

Requirements:

• Every URL that receives organic traffic must be mapped
• Every URL with backlinks must be mapped
• Every indexed URL should be mapped (or deliberately consolidated)
• Map to the most relevant new URL — not just the homepage

For large sites, prioritize:

1. Pages with organic traffic (last 12 months)
2. Pages with external backlinks
3. All remaining indexed pages

3. Plan Your Redirects

• Use 301 redirects for permanent URL changes (not 302)
• Avoid redirect chains — old URL should redirect directly to the new URL, not through an intermediate
• Map to the most specific equivalent — a product page should redirect to the equivalent product page, not the category page
• Do not redirect everything to the homepage — this tells Google you have removed all content

For redirect best practices, see our redirect management guide.

4. Audit the New Site Before Launch

Before going live, crawl the staging/new site and verify:

• All key pages exist at their new URLs
• Title tags and meta descriptions are present and unique
• Canonical tags are self-referencing and correct
• Internal links point to new URLs (not old URLs that will redirect)
• Schema markup is implemented correctly
• Robots.txt allows crawling of all important content
• XML sitemap includes all new URLs
• Page speed meets Core Web Vitals thresholds
• Mobile rendering works correctly across all templates

5. Prepare Updated Sitemaps

Create two sitemaps:

• New sitemap — containing all new URLs, ready to submit to Search Console on launch day
• Old sitemap (optional) — useful for monitoring how quickly Google processes the redirects

Review our XML sitemap guide for format requirements.

Migration Day

Launch Sequence

1. Implement all 301 redirects simultaneously with the new site launch
2. Submit the new XML sitemap to Google Search Console
3. Test redirects — verify a sample of high-priority URLs redirect correctly
4. Test the new site — spot-check key pages for content, meta tags, schema, and functionality
5. Verify robots.txt — ensure nothing important is blocked on the live new site
6. Update Google Search Console — if changing domains, use the Change of Address tool
7. Update Google Analytics — ensure tracking is active on the new site

If Changing Domains

• Verify the new domain in Google Search Console before migration
• Use the Change of Address tool in Search Console to notify Google
• Keep the old domain active with redirects for at least 12 months — preferably indefinitely
• Update external links where possible — social profiles, business directories, partner sites

Post-Migration Monitoring

Week 1: Daily Monitoring

Check these metrics daily for the first week:

• Crawl stats in Google Search Console — is Googlebot discovering the new URLs?
• Index coverage — are new URLs being indexed? Are old URLs being removed?
• Redirect validation — are any redirects broken or creating chains?
• 404 errors — monitor for pages that were missed in the URL mapping
• Organic traffic — expect some fluctuation but flag drops greater than 30%

Weeks 2-4: Stabilization

• Keyword rankings — should begin stabilizing or recovering
• Indexed page count — should approach pre-migration levels
• Crawl errors — address any persistent 404s or server errors
• User-reported issues — broken bookmarks, broken links from external sites

Months 2-6: Recovery and Growth

• Compare traffic to baseline — are you back to pre-migration levels?
• Keyword ranking comparison — which keywords recovered, which are still down?
• New content indexation — are new pages published post-migration being indexed normally?
• Backlink transfer — are external links being followed through redirects?

Common Migration Mistakes

Incomplete URL Mapping

Missing URLs in your redirect map means those pages return 404 errors, and any link equity they carried is lost. For large sites, use a combination of:

• Full crawl data
• Google Search Console URL list
• Google Analytics landing page report
• Backlink database export

Internal Links Pointing to Old URLs

After migration, internal links should point directly to new URLs — not to old URLs that redirect. While redirects pass most link equity, direct internal links are always better. Update all internal links in your CMS, templates, and content.

Removing Redirects Too Early

Redirects from the old URLs need to stay in place for at least 12 months. Removing them after a few weeks means search engines — and users with bookmarks — hit 404 pages.

Not Monitoring Long Enough

Migration impacts can take 3-6 months to fully manifest. Continue monitoring keyword rankings, traffic by landing page, and indexation counts for at least six months after migration.

Migrating During a Redesign and Content Overhaul Simultaneously

Changing URLs, design, and content all at once makes it impossible to diagnose problems. If you change everything and traffic drops, was it the redirects, the new design, or the new content? Separate major changes where possible — migrate URLs first, then redesign, then overhaul content.

Recovery Plan

If traffic drops significantly after migration:

1. Check redirect implementation — are all redirects working? Any chains or loops?
2. Verify indexation — are new URLs being indexed? Run “site:” searches for key pages
3. Check robots.txt — is anything accidentally blocked?
4. Validate canonical tags — are they pointing to the correct new URLs?
5. Review Google Search Console — check for manual actions, security issues, or crawl errors
6. Compare content — did any critical content change or get removed during migration?
7. Check page speed — did the new site introduce performance regressions?

Use a comprehensive audit tool to crawl the post-migration site and compare against your pre-migration baseline. Systematic comparison reveals issues that manual spot-checking misses.