Website migrations are high-stakes. Done well, a migration preserves your search rankings and sets you up for growth. Done poorly, it can erase years of organic traffic in a matter of days — and recovering from a botched migration often takes 6–12 months.

The migrations that go wrong almost always share the same root cause: insufficient preparation. Teams focus on the new design and content, and treat SEO as a last-minute checklist item. By the time someone realizes that hundreds of URLs have changed without redirects, the damage is done.

This checklist is designed to prevent that. It covers every phase of a migration — from initial planning through post-launch monitoring — with specific, actionable steps.

Phase 1: Pre-migration audit (2–4 weeks before)

Crawl your existing site completely

Before changing anything, you need a complete inventory of what you have. Run a full crawl of your current site and export everything: URLs, titles, meta descriptions, status codes, internal links, inbound link counts, and crawl depth.

This crawl becomes your baseline. You'll compare everything against it after the migration to catch issues.

Build your content inventory

From your crawl data, build a spreadsheet of every URL on the current site. For each URL, document:

Pages with backlinks and organic traffic are your highest-priority items. These must have correct redirects. A content audit helps you decide which pages to keep, merge, or retire.

Create your redirect map

For every URL that's changing, document the old URL and the new URL it should redirect to. This is your redirect map — the single most critical document in any migration.

Rules for redirect mapping:

Benchmark your current performance

Record your baseline metrics before the migration: organic traffic by page, keyword rankings for your top 50 terms, Core Web Vitals scores, indexed page count in Google Search Console, and crawl stats. You'll compare against these after launch.

Phase 2: Staging validation (1–2 weeks before)

Crawl the staging site

Set up the new site on a staging URL and crawl it thoroughly. Compare the staging crawl against your baseline crawl. Look for:

Test your redirects

Implement your redirect map on staging and test every redirect. A single typo in a redirect rule can send traffic to a 404 page. Automated testing is essential here — you can't manually verify hundreds of redirects.

Validate technical SEO elements

Confirm that the new site has:

Phase 3: Launch day

Implement redirects on production

Deploy your redirect map to the production server. This should happen simultaneously with the DNS cutover or new site deployment.

Submit the new sitemap

In Google Search Console, submit your updated XML sitemap immediately after launch. This tells Google to crawl your new URL structure promptly.

Request indexing for priority pages

Use Google Search Console's URL Inspection tool to request indexing for your 10–20 most important pages. This accelerates the re-indexing process for your highest-value content.

Phase 4: Post-launch monitoring (1–8 weeks after)

Crawl the live site immediately

Within 24 hours of launch, run a full crawl of the live site. Compare it against both your baseline crawl and your staging crawl. Look for:

Monitor Search Console daily

For the first two weeks, check Search Console daily. Watch for:

Track rankings and traffic weekly

Compare organic traffic and keyword rankings against your pre-migration benchmarks. Some fluctuation is normal in the first 2–4 weeks as Google re-processes your site. Significant drops lasting more than 3 weeks indicate a problem that needs investigation.

Common migration mistakes

Forgetting to redirect non-www to www (or vice versa). If your old site used www.example.com and your new site uses example.com, you need redirects for both the URL changes and the domain change.

Blocking the new site with robots.txt. Staging sites often have robots.txt rules that block all crawlers. If these carry over to production, your entire site becomes invisible to search engines.

Losing internal links. Content management systems sometimes rewrite internal links during migration. Crawl the new site and verify that internal links point to correct, live URLs.

Not monitoring long enough. The full impact of a migration can take 8–12 weeks to materialize. Don't declare victory after one week of stable traffic.

Tools for migration SEO

A website crawler is non-negotiable for migrations. You need to crawl before, during staging, and after launch — and compare the results at each stage. IATO's comparison features let you diff two crawls side by side, highlighting new 404s, changed URLs, and structural differences. Combined with our visual sitemap builder, you can see exactly how your site's architecture changed and catch issues before they impact rankings.

Migrations don't have to be traumatic. With thorough preparation and systematic post-launch monitoring, you can preserve your search equity and come out stronger on the other side.