What does site migration mean, and how do you avoid losing traffic?

16 October 2026 · By John Carlsson

Site migration means moving a website in a way that changes its URLs or the infrastructure behind it, such as switching to HTTPS, changing domain or changing hosting. To limit traffic loss, map every old URL to its new address, use server-side permanent redirects, keep them for at least a year, and monitor Search Console while Google processes the change.

What counts as a site migration?

Google calls this a site move and splits it into two kinds. A move with URL changes includes switching from HTTP to HTTPS, changing your domain name, for example from example.com to example.net, merging domains or hostnames, and changing URL paths. A move without URL changes covers work such as changing your hosting provider, where the addresses people visit stay the same. The first kind carries more risk, because Google has to discover, crawl and process every new URL and connect it to the old one.

How should you prepare before the move?

Most problems with migrations come from gaps in preparation. Google's guidance includes these steps:

Set up the new site and its content, ideally on the same content management system, with TLS certificates in place for HTTPS.
Prepare the new robots.txt, and remember to remove any temporary noindex or blocking rules once the move starts.
Verify both the old and new sites in Search Console, and check the new domain for any leftover manual actions or URL removals.
Make sure your server can cope, because Google crawls more heavily after a migration.
Decide what happens to content you are not moving. Google suggests returning 404 or 410 for those URLs.

Next, build a full list of old URLs from your sitemaps, server logs, analytics and content management system, including images, videos, JavaScript and CSS files. Map every old URL to its new address. On the new site, update canonical tags, hreflang annotations and internal links so they point straight at the new URLs.

How should the redirects be set up?

Redirects are what carry visitors and search signals from the old URLs to the new ones. Google recommends server-side permanent redirects where possible, and says that 301 and other permanent redirects do not cause a loss in PageRank. Google treats 301 and 308 as permanent and uses them as a signal that the target URL should be canonical.

A few rules keep redirects working well:

Redirect each old URL to its closest matching new page, not to the homepage.
Avoid chains. Google says Googlebot can follow up to 10 hops, but advises redirecting straight to the final destination.
Use client-side redirects, such as JavaScript, only as a last resort.
Keep the redirects for as long as possible, generally at least one year.

Small and medium sites can generally move everything at once. Large sites can move in sections.

What should you do on the day and afterwards?

Turn on the redirects, then confirm that canonical tags and robots rules point to the new URLs. Test a sample of old URLs with the URL Inspection tool or a command line tool. If you changed domain or subdomain, submit a Change of Address in Search Console for the old site. Google updated its guide in June 2026 to say this should be done for every verified variant of the domain, including www and non-www. You do not need it for an HTTP to HTTPS move or for path changes within the same domain. Submit the new sitemap and remove the old one.

Google warns you to expect temporary fluctuation in rankings during the move. Googlebot has to visit every old and new URL at least once, and for small and medium sites it can take a few weeks or more for most pages to move, with larger sites taking longer. During that time, watch the Sitemaps and Pages reports and your query data in Search Console, check your server logs for Googlebot activity and unexpected error codes, and confirm in analytics that traffic falls on the old site as it rises on the new one. Finally, ask sites that link to you to update their links, and update your own profiles and adverts, so fewer visits rely on redirects.

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Frequently asked questions

How long should I keep redirects after changing domain?

Google recommends keeping redirects for as long as possible, and generally for at least one year. That gives Google time to transfer signals to the new URLs and gives visitors who use old links or bookmarks a working route. Google also suggests asking sites that link to you to update their links, so fewer visits depend on the redirects over time.

Do I need the Change of Address tool when moving to HTTPS?

No. Google says the Change of Address tool is for domain or subdomain changes. You do not need it when moving from HTTP to HTTPS, switching between www and non-www on the same domain, or changing URL paths within a domain. For those moves, permanent redirects, updated canonical tags and a new sitemap are the main signals.