A website migration SEO checklist has one job: make sure every old URL that earns traffic or links lands on its closest new equivalent with a server-side 301 redirect. Google says to keep those redirects for at least a year. Inventory first, map second, launch third, then watch crawl and rankings for months.
Most migrations that lose traffic fail on the first two steps. The new site looks finished, the launch date is fixed, and nobody owns the spreadsheet that connects old URLs to new ones. This checklist follows the order we use on client moves and ties each step to the Google documentation behind it, plus one step most guides skip: keeping AI search crawlers in the plan.
A website migration SEO checklist starts with a URL inventory
Start by listing every URL that matters before anyone touches the new build. Pull URLs from a full crawl, your XML sitemaps, Google Search Console's page reports, analytics landing pages and your backlink tool. The crawl shows what exists. The other sources show what earns traffic, links and conversions, and those are the pages a site migration cannot afford to drop.
Tag each URL with its traffic, its inbound links and a decision: keep, merge or retire. Retired pages need a deliberate answer too. Google's site move guide says that if you remove content in the move, those URLs should correctly return a 404 or 410 on the new site (Google Search Central). If you are moving off a platform such as Wix or WordPress, our WordPress alternative guide explains why keeping URL paths stable is the cheapest SEO decision you can make.
Build the 301 redirect map one URL at a time
The 301 redirect map is the core of any SEO site migration. Each row pairs an old URL with the single most relevant new URL. Google treats 301 and 308 status codes as permanent moves and recommends server-side redirects. JavaScript redirects are a last resort, because "Google might never see it if rendering of the content failed" (Google Search Central).
Point every redirect straight at its final destination. If chains are unavoidable, Google advises keeping them "ideally no more than 3 and fewer than 5" hops (Google). Old chains from previous redesigns are common, so flatten them while you build the map. Resist redirecting retired pages to the homepage in bulk; send them to the closest topical page or let them return a 404. Then test the full map on staging with a crawler before launch day, which is the same discipline our website audit checklist applies to live sites.
Launch day for an SEO site migration: redirects, sitemaps and the Change of Address tool
Launch day is short if the map is ready. Deploy the redirects, remove any staging noindex or password, and submit sitemaps for the new URLs in Search Console. If the domain itself changes, use the Change of Address tool, which keeps working on the move for 180 days. Google asks you to "maintain the redirects for at least 180 days" in that case, and longer if old URLs still get search traffic (Google Search Console Help).
Expect a crawl spike. Google says it "will temporarily crawl your new site more heavily than usual" after a migration, so confirm your server can handle it (Google). Keep the old domain registered as well. Google recommends paying for it for at least a year so nobody else can buy it and use it for malicious purposes (Google). Our technical SEO team runs this launch sequence on client moves and owns the monitoring that follows.
Keep AI search crawlers in the website migration plan
A site migration can quietly remove you from AI answers. New hosting, a new CDN or a security plugin often ships with a fresh robots.txt or bot-blocking rules. OpenAI's crawler documentation states that sites opted out of OAI-SearchBot "will not be shown in ChatGPT search answers," and that changes to robots.txt take about 24 hours to register. Opted-out sites can still appear as navigational links (OpenAI).
Add the AI crawlers to the launch checklist next to Googlebot. Compare the old and new robots.txt line by line, check firewall rules for user-agent blocks, and confirm your key pages render their links in HTML, a problem we covered in AI crawlers and JavaScript. After launch, watch AI referrals in your analytics so a drop shows up in days.
Site migration timelines: weeks for Google, months for traffic
Plan for recovery to take longer than the launch. Google's guide says a small to medium-sized website "can take a few weeks for most pages to move, and larger sites take longer" (Google). At Search Central Live in Barcelona on October 2, Gary Illyes reportedly put a typical site move at one to three months and the slowest at six months to more than a year, according to an attendee recap reported by Search Engine Journal. SEJ cautions that the published recaps do not define "typical" or report a sample size.
Domain changes can take longer still. In a practitioner study of 892 domain migrations that used third-party traffic estimates, Dan Taylor found an average of 523 days before the new domain matched the old one's organic traffic, and 17 percent had not recovered after 1,000 days (Search Engine Journal). Set stakeholder expectations with those ranges, and track indexed pages, rankings for your top URLs and AI visibility weekly. The Search Console AI performance report adds that last signal to the same dashboard.
Website redesign without losing SEO: separate the risks
A domain move and a redesign are two migrations, and running them together compounds the risk. Google says that if you combine a site move with a redesign of content and URL structure, "you will probably see some traffic loss as Google might need to relearn and reassess the individual pages" (Google). When the calendar allows, move first, let rankings settle, then redesign.
When both must happen at once, keep as much constant as you can: URL paths, title tags, headings and internal links on the pages that earn traffic. Change the design layer and leave the content of those pages alone until the move has settled. If you are planning a replatform or redesign in 2026, talk to us before the launch date is set, since the redirect map takes longer to build than most teams expect.
