Site migrations are one of the most common ways established websites lose search traffic. A new domain, a redesign, a switch to a new CMS, or a restructure of URLs can each undo years of earned rankings if redirects are missing, staging settings go live, or internal links point at pages that no longer exist. Most of that damage is preventable. Google publishes detailed guidance on moving a site with URL changes, and the work follows a predictable pattern: plan before, execute carefully at launch, and monitor closely afterward. This checklist walks through each stage.

What Counts as a Migration

  • Domain change: moving from one domain to another, such as a rebrand.
  • Protocol change: moving from HTTP to HTTPS.
  • Host change: switching between www and non-www, or moving to a subdomain.
  • URL structure change: new paths or slugs on the same domain.
  • Platform change: a new CMS, which often changes URLs and templates at the same time.
  • Redesign: new templates, navigation, and content, sometimes with URL changes.

Moves that change URLs carry the most risk. A redesign that keeps every URL the same is lower risk, but it can still drop content, internal links, or metadata from templates.

Before the Migration

1. Benchmark your current performance

Export data you'll want to compare against later: clicks, impressions, and top pages and queries from Search Console, organic landing pages from analytics, and your indexed page count. Without a baseline, you can't tell whether the migration caused a problem.

2. Inventory every old URL

Google recommends building a list of old URLs from multiple sources: your sitemaps, server logs, analytics, and your CMS. Include images, videos, and other assets that matter. Don't forget URLs that have external backlinks, since those carry earned value. The guide to reclaiming lost backlinks covers how to find them.

3. Map each old URL to a new URL

For every old URL, decide its new destination. The rule is one-to-one wherever possible: each old page redirects to its closest equivalent. Google's guidance specifically warns against redirecting many old URLs to one unrelated page, such as the new homepage, except where content has genuinely been consolidated. Irrelevant redirects can be treated as soft 404s, as covered in the soft 404 guide.

Keep the map in a spreadsheet. It becomes your redirect source, your test list, and your troubleshooting reference.

4. Prepare the new site

  • Test the new site thoroughly in a staging environment.
  • Make sure titles, meta descriptions, headings, and structured data carried over to the new templates.
  • Update canonical tags and hreflang annotations to use the new URLs.
  • Update internal links to point directly at new URLs, rather than relying on redirects.
  • Prepare the new robots.txt.
  • Make sure your new server can handle increased crawling. Google crawls more heavily after a migration.

5. List every staging block you'll need to remove

Staging sites are usually protected with noindex tags, a blocking robots.txt, or password protection. Google's guidance suggests listing exactly where these are so you can remove them at launch. Launching with a staging noindex or Disallow: / is one of the most common and most damaging migration mistakes.

6. Write and test the redirects

Use server-side permanent redirects, 301 or 308, wherever possible. Google advises redirecting directly to the final destination and avoiding chains. If old URLs already redirect from a previous change, update those rules too so nothing passes through multiple hops. The .htaccess redirects guide covers how to write rules safely, and the .htaccess Redirect Generator builds them without regular expressions.

7. Verify both sites in Search Console

Keep verification working on the old site and set up the new one, including all its variants, before launch.

Launch Day

  • Remove staging blocks: noindex tags, blocking robots.txt rules, and password protection.
  • Activate redirects from every old URL.
  • Spot-check redirects on a sample of important URLs, including your top traffic pages and most-linked pages. The Redirect & Header Checker shows every hop and the final status for each URL.
  • Confirm key pages are indexable with the Indexability Checker.
  • Submit sitemaps. Google suggests keeping a sitemap of the old URLs as well as submitting the new one, so Google discovers the redirects. Redirect warnings on the old sitemap are expected. Remove the old sitemap once Google is using the new one. Validate the new sitemap with the XML Sitemap Validator.
  • Use the Change of Address tool in Search Console if you moved to a new domain or subdomain. Google notes it isn't needed for HTTP-to-HTTPS moves, www changes, or path changes within the same domain.

After the Migration

Monitor closely for the first weeks

  • Search Console: watch the Page Indexing report for spikes in 404s, redirect errors, or excluded pages, and watch the Sitemaps report for the new sitemap being processed.
  • Performance: compare clicks and impressions against your benchmark. Expect traffic on the old site to fall as traffic on the new site rises.
  • Server logs: check that Googlebot is crawling the new URLs and look for unexpected error codes.
  • Crawl the new site for broken internal links. The Broken Link Checker checks every link on a page.

Expect some fluctuation

Google says rankings can fluctuate during a move, and that for a medium-sized site it can take a few weeks or more for Google to start showing the new URLs instead of the old ones. Larger sites take longer. Short-term fluctuation is normal. A sustained drop usually points to a specific problem, such as missing redirects, blocked pages, or lost content.

Keep redirects in place

Google recommends keeping redirects for as long as possible, generally at least a year. In practice, keep them indefinitely if you can. Old URLs live on in backlinks, bookmarks, and other sites' content for years.

Update what you control externally

Update your Business Profile, social profiles, citations, and important backlinks you have influence over to point at new URLs. Direct links are better than links that rely on redirects.

If Traffic Drops After a Migration

  • Check for leftover staging blocks first. It's the fastest catastrophic problem to fix.
  • Test redirects on the old URLs that lost the most traffic.
  • Compare old and new versions of important pages for missing content, titles, or internal links.
  • Check the Page Indexing report for patterns in excluded URLs.

The step-by-step guide to diagnosing a traffic drop covers the full process, and the guide to auditing redirect chains helps clean up any hops the migration created.

The Short Version

  • Benchmark everything before you start.
  • Inventory and map every old URL one-to-one.
  • Update canonicals, hreflang, and internal links to new URLs.
  • Use direct, server-side permanent redirects with no chains.
  • Remove every staging block at launch.
  • Submit old and new sitemaps, and use Change of Address for domain moves.
  • Monitor closely, expect some fluctuation, and keep redirects for the long term.