Website migration
A website migration is any significant change to a site's location, address, platform or structure, such as moving to a new host, changing domain, switching CMS or restructuring URLs, that can affect how visitors and search engines reach it.
Migration covers several different moves with different risks. A host move changes where the site lives but should keep every address the same. A domain change or a switch from HTTP to HTTPS changes every address. A platform change or a redesign often changes the URL structure, the content and the templates at once. The more of these happen together, the harder it becomes to tell what caused a problem afterwards.
The search engine risk comes from addresses. Rankings belong to individual URLs; if an old address disappears without a forwarding rule, the value it built up is lost along with any visitor using an old link or bookmark. Internal links, the sitemap and canonical tags should also point straight at the new addresses rather than relying on redirects.
How it works
A careful migration starts with an inventory: every URL the site has, from a crawl, the XML sitemap and the pages that receive traffic or links, plus current rankings and traffic as a baseline. Each old address is mapped to its new equivalent. Where content is removed, it is mapped to the closest relevant page rather than the home page.
The new site is built and checked on a staging site or a temporary address. Before launch, the DNS TTL is lowered so the switch spreads quickly. At launch, 301 redirects go live from every old address to its new one, the DNS or domain settings are switched and the new site is crawled to catch broken links, missing pages and leftover staging settings such as a site-wide noindex.
For a domain change, Google Search Console has a change of address tool for telling Google the site has moved, and both the old and new domains should be verified there. The old domain must stay registered and keep redirecting for a long time; letting it expire throws away the redirects and the links pointing at it. Email often depends on the same domain and DNS, so it needs its own plan.
Example
A legal practice rebrands and moves from its old domain to a new one, with a new CMS and a slightly different page structure. The team exports all 140 URLs from the old site, maps each one to its new address in a spreadsheet and implements the redirects on the old domain. Pages for a discontinued service redirect to the most closely related practice-area page.
On launch day, they test a sample of old addresses with a redirect checker, submit the new XML sitemap in Search Console and use the change of address tool. They watch the coverage and traffic reports over the following weeks; a temporary dip is normal, while a page that loses all its traffic points to a missing or wrong redirect, which is fixed as it appears.
Why it matters for your business
Most of a site's search visibility and referral traffic is tied to its existing addresses, so a migration done carelessly can wipe out years of work in a day. Done well, a host move is invisible to visitors and even a domain change usually recovers within weeks. The cost of planning, mapping and testing is small compared with the cost of rebuilding lost traffic. If you are only changing hosts, keep everything else the same for that move; save the redesign or restructure for a separate step.
Common mistakes
- Launching a new site without redirects from the old URLs.
- Redirecting every old page to the home page instead of to its closest equivalent.
- Carrying a staging noindex setting or password onto the live site.
- Letting the old domain expire after a domain change, which breaks every redirect and old link.
Questions people ask
Will a website migration hurt my SEO?
It can, but it does not have to. Host moves done correctly should have no effect. Domain changes and restructures often cause a temporary dip while search engines process the redirects. Lasting losses usually trace back to missing redirects, removed content or blocked crawling, which careful planning prevents.
How long does a website migration take?
It depends on the type. A small host move can take a day or two including testing, while a domain change or redesign with URL mapping can take weeks of planning. Search engines then need time to process the change, often a few weeks for a small site.
Do I need to keep my old domain after migrating?
Yes. Keep it registered and keep the redirects running for at least a year, and ideally for as long as old links and bookmarks still send visitors. If it expires, the redirects stop and someone else could register the name and capture that traffic.
