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Website migration without losing SEO

Moving to a new CMS or domain? You keep your search visibility by sending every old URL to the right new page with a permanent redirect, and by carrying over the content and signals search engines already use. Below is the checklist we follow, based on Google's own guidance.

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Redirect map

Example
Example redirect map with status codes and page parity checks
Old URL / New URLStatus
/services.php?id=12/services/cms-modernization/301
/about-us.html/about/308
/news/launch-2019/blog/launch/301
/spring-offer/contact/302Make it permanent

Page parity

  • Title and meta descriptionMatch
  • H1 and body contentMatch
  • Canonical and hreflangMatch
  • Structured dataMatch

Why rankings drop after a migration

A migration keeps its search visibility when every old URL leads to the matching new page and each page keeps the content and signals search engines already trust. When rankings drop, the cause is usually on this list, and each one can be checked before launch.

Changed URLs without permanent redirects

Old addresses return errors or temporary redirects, so search engines treat the new pages as new.

Lost or merged content

Pages that ranked are dropped, cut down or folded into a page that answers a different question.

Missing page signals

Titles, meta descriptions, canonicals, hreflang or structured data do not make it to the new templates.

Broken internal links

Menus and body links still point at old URLs, or at pages that no longer exist.

Content rendered only by JavaScript

The HTML the server sends is nearly empty and the text only appears after scripts run.

Slower pages

New templates load more code or heavier images, and key pages get slower.

Staging noindex left on

A noindex rule meant for the test site ships to production.

robots.txt blocks

A rule written for staging stops crawlers from reaching the live site.

Even a clean move needs time. Google says to expect some ranking changes while it recrawls a moved site, and that a medium-sized site can take a few weeks or more before the new URLs replace the old ones in results. Larger sites take longer. Google Search Central, site moves

Website migration SEO checklist

Tick items as you go. Your progress is saved in this browser, so you can come back to it.

Before

Before

0 of 4

Know what you have and how it performs today.

  • List every page, PDF, image and video URL from your sitemaps, analytics, server logs and a full crawl. Start with the URLs that get the most traffic and links.

    Google's guidance

  • Record where you rank, which pages bring visits and how fast key templates load, so you have something to compare with after launch.

  • One row per old URL with the page it should go to. Pages you drop on purpose return a 404 or 410 instead of redirecting to the homepage.

    Google's guidance

  • Every URL you keep is one less redirect. Google notes that keeping the same site architecture helps pass signals to the new site.

    Google's guidance
Build

Build

0 of 5

Make the new site carry everything that ranks today.

  • Move them with the content, page by page, rather than rewriting them in the new templates.

  • Each new URL gets a self-referencing canonical, and hreflang annotations and structured data point at the new URLs.

    Google's guidance

  • Update menus, footers and links in body copy so they reach the new page directly instead of passing through a redirect.

    Google's guidance

  • Look at the HTML the server sends. Main text, links and metadata should be there without depending on scripts that can fail.

  • Protect the test site with a password, noindex or robots.txt rules, and write down exactly what to remove on launch day.

    Google's guidance
Launch day

Launch day

0 of 4

Switch on the redirects and open the site to crawlers.

  • Server-side permanent redirects from each old URL straight to its final new URL. Avoid chains. Google can follow up to 10 hops but advises going directly to the final destination.

    Google's guidance

  • Take off the noindex rules and robots.txt blocks used during the build. Google lists forgotten blocks as a common migration mistake.

    Google's guidance

  • Publish a sitemap with the new URLs, submit it in Search Console and check that robots.txt only blocks what you mean to block.

    Google's guidance

  • For a move to a new domain or subdomain, after the redirects are live. It does not apply to HTTP to HTTPS or path-only changes.

    Google's guidance
After launch

After launch

0 of 3

Watch the move settle and keep the signals in place.

  • Watch the indexing and sitemaps reports in Search Console, fix 404s and redirect errors as they appear, and compare with your benchmark.

    Google's guidance

  • Google recommends keeping them as long as possible, generally at least one year, and at least 180 days when you use the Change of Address tool.

    Google's guidance

  • Check that robots.txt still allows the search and AI crawlers you allowed before, and keep headings, lists and answers in the HTML so AI answers can still find and cite your pages.

How Sengo Replica handles this

Sengo Replica is our website migration service for teams changing platforms. It rebuilds your site 1:1 from the live site on the new platform, pixel for pixel and responsive, and moves your content into structured headless CMS models, from any source to any destination. Before cutover, we check the items on this list, because keeping your search visibility is part of the plan from day one.

Request a free Replica pilotSee how Sengo Replica works
  • Same URLs where possible, and a one-to-one redirect map where not
  • Titles, meta descriptions, headings, canonicals, hreflang and structured data carried over
  • Content present in the HTML the server sends
  • Sitemaps, robots.txt and staging blocks checked before launch

Sengo moved its own site, about 600 pages, off WordPress in one night.

Read the Ploy case study

Sengo is a Sitecore Silver partner, a certified Optimizely partner, a certified Kentico Xperience partner, and a Contentful and Storyblok partner.

Website migration SEO questions

How long until rankings settle after a migration?

Google says there is no fixed timeline. For a medium-sized site it can take a few weeks or more before Google shows the new URLs instead of the old ones, and larger sites take longer. The move is complete once Googlebot has visited every old and new URL at least once, and that speed depends on the number of URLs and your server speed. Expect some ranking movement in that period.

Should I change URLs during a migration?

Only when you have a reason to. Every changed URL needs a redirect, and Google advises changing one thing at a time, for example moving the domain first and changing the layout later. Google also notes that keeping the same site architecture helps pass signals to the new location. If you do change URLs, map each old one to its closest new page.

Should I use a 301 or a 302 redirect?

Use a permanent redirect, 301 or 308, for a migration. Google treats a permanent redirect as a signal that the new URL should be shown in search results, and says 301 and other permanent redirects do not cause a loss in PageRank. A 302 is temporary, so Google keeps showing the old URL. Send each old URL straight to its final destination rather than through a chain.

How long should I keep redirects after a migration?

Google recommends keeping them as long as possible, generally at least one year, so it can transfer signals and recrawl links from other sites. If you use the Change of Address tool in Search Console, keep them at least 180 days, and longer if they still get traffic from Google Search. For visitors, Google suggests considering keeping them indefinitely.

Does a redesign hurt SEO?

It does not have to, but changing design, content and URLs at the same time makes problems hard to trace. Google says that combining a site move with a redesign of content and URL structure will probably cause some traffic loss while it reassesses pages, and advises making one change at a time. A 1:1 rebuild keeps pages the same, so you can measure the move on its own and redesign afterwards.

Do I need the Change of Address tool?

Only when the domain or subdomain changes, for example from example.com to example.org. Google says not to use it for HTTP to HTTPS moves, path changes within the same site, www to non-www changes or a hosting change with no URL changes. Use it after the redirects are live.

Will a migration change how AI answers cite my site?

It can if crawlers lose access or the content changes shape. AI search tools and assistants can only cite pages their crawlers can reach. Keep the robots.txt rules for the crawlers you allowed before, keep content in the HTML rather than behind scripts, and keep the headings and direct answers that made your pages easy to quote.

Planning a platform move?

Start with a free Sengo Replica pilot, or tell us about your current site and where it needs to go.

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Sources

Google documentation checked on October 29, 2026.