Website Migration SEO: A Checklist for Website Redesigns

Website migration SEO is the work of protecting search rankings, organic traffic and enquiries when a website changes in a way that affects how search engines crawl and index it. A redesign, a new domain or a move to a different CMS can each put years of organic visibility at risk, which is why many organisations bring in SEO migration support for UK businesses before the new website is built rather than after it launches.

The risk is manageable when the work happens in the right order. The SEO migration checklist below is split into three phases, covering what to do before launch, on launch day and in the weeks that follow. In brief, it runs as follows.

1. Crawl the current website and record rankings, traffic and conversions as a baseline.
2. Build a full inventory of existing URLs, including documents and media files.
3. Map every old URL to its closest equivalent on the new website.
4. Check content parity so ranking pages keep their copy, headings and metadata.
5. Build the new website on a staging environment kept out of the index.
6. Launch with server-side 301 redirects, self-referencing canonicals, a clean robots.txt file and new XML sitemaps.
7. Check internal links, structured data and analytics tags on the live website, then submit a Change of Address if the domain has changed.
8. Crawl again after launch to fix errors and redirect chains, then monitor indexing, rankings, traffic and Core Web Vitals.

Each step is explained in more detail below, along with the mistakes that most often cause traffic loss and how long rankings can take to settle. The principles are the same for a small brochure website and a large B2B website, although the mapping work grows with the number of URLs.

What Is Website Migration SEO

Website migration SEO covers any change that alters a website’s URLs, content, platform or the way search engines reach it. The aim is to carry over the signals the website has built up, such as links, relevance and indexing history, so search engines treat the new version as a continuation of the old one rather than a new website starting from nothing.

Migrations come in several forms and the level of risk depends on how much changes at once. A redesign that keeps the same domain and URL structure is usually the lowest risk, provided content and metadata carry over intact. A structure change that renames sections or URLs needs a full redirect map, while a domain change or a move from HTTP to HTTPS changes every URL on the website. A CMS or platform change often combines several of these at the same time. A hosting move that keeps every URL the same carries less risk again and Google publishes separate guidance on changing hosting.

Each extra change adds another variable to investigate if traffic drops after launch. Our guide to migrating to WordPress covers the platform side of this in more detail.

Why Rankings Drop After a Website Migration

Rankings drop after a migration when search engines lose the connection between old pages and their new equivalents. Every indexed URL has built up links, relevance and history over time and if the old URL returns an error or redirects somewhere unrelated, those signals are weakened or lost.

Missing or incorrect redirects are the most common cause, although they are not the only one. Content removed during a redesign, rewritten title tags, a new navigation that buries pages several clicks deep and staging settings left in place at launch can all reduce visibility. Google’s guidance on site moves with URL changes also warns that redirecting many old URLs to one irrelevant destination, such as the home page, can confuse users and may be treated as a soft 404.

Some movement is normal even when everything is done correctly. Google says to expect temporary fluctuation in rankings while it recrawls and reindexes a website, so the goal is to keep that period short and avoid permanent losses.

Planning an SEO Website Redesign in Three Phases

An SEO website redesign works well when SEO is part of the project plan from the first workshop, not a task added in the week before launch. Priority Pixels structures its migration work around pre-migration planning, technical implementation and post-launch monitoring and the checklist here follows the same three phases.

For Priority Pixels clients, planning and implementation usually take four to eight weeks, followed by three to six months of monitoring after launch. The exact timeline depends on the size of the website, the amount of content and the technical work involved. Our website redesign planning guide covers the wider project, from setting goals through to sign-off.

The Pre-Launch SEO Migration Checklist

Most of the work in a successful migration happens before launch, starting with a full crawl of the current website. A crawler such as Screaming Frog records every URL, status code, title tag, meta description, canonical and internal link, giving you a snapshot to compare against later.

Record performance at the same time. Export rankings, clicks and impressions from Google Search Console alongside organic sessions and conversions from GA4, so there is a baseline to measure against after launch. Include enough history to account for seasonal patterns, because a dip that looks like a migration problem can simply be a quieter month.

The URL inventory comes next. Google suggests building it from your sitemaps, server logs, analytics and the links report in Search Console, together with a full export from the CMS. PDFs, images and other documents belong in the inventory too, because they often attract links and search traffic of their own.

Each old URL then needs a destination on the new website. The redirect map is usually a spreadsheet that pairs old and new URLs and records which pages are being merged or removed. The example below shows the kind of decisions it needs to capture.

Content parity is the next check. Pages that rank well should keep their core copy, headings, title tags and meta descriptions unless there is a clear reason to change them, because rewriting everything while the URLs move makes it harder for search engines to recognise the page. Structured data, alt text and internal links on key pages need the same attention.

The new website should be built on a staging environment that search engines cannot index. Google’s documentation on blocking indexing with noindex explains that the rule only works when the page is not also blocked in robots.txt and many teams add password protection to staging for extra certainty. Keep a list of every setting so each one can be removed at launch.

What to Check on Launch Day

Launch day is when the redirect map goes live and the settings prepared on staging are switched over. Priority Pixels creates 301 redirect rules for every page in the map, handles parameter variations and plans for removed content, then double-checks the redirects again once the website is live.

Redirects should be permanent and set up on the server wherever possible. Google’s guidance on redirects and Google Search explains that a permanent redirect tells its indexing pipeline the target should be canonical and that server-side redirects are the most likely to be interpreted correctly. Google also advises pointing each old URL straight to its final destination, because redirect chains add latency for users.

Canonical tags, robots.txt and sitemaps need checking on the live website alongside the redirects. Each new page should carry a self-referencing canonical, as Google’s guidance on specifying canonical URLs recommends and any staging noindex rules should be gone. The robots.txt file should allow crawling of the new structure and a fresh XML sitemap of the new URLs should be submitted in Search Console, following Google’s advice on building and submitting a sitemap.

Internal links, structured data and tracking complete the launch checks. Internal links should point directly to the new URLs rather than relying on redirects, structured data should be validated on the new templates and Google Tag Manager and GA4 should be recording sessions and conversions correctly. If the domain has changed, submit a Change of Address in Search Console for the old property, as Google’s site move guidance recommends and make sure every variant of the old and new domains is verified.

What to Check After Launch

The first few weeks after launch show whether the migration has held its rankings. Start with a fresh crawl of the live website to find broken links, 404 errors, redirect chains and pages that have lost their canonical or metadata, then crawl the old URL list to confirm each one redirects to the right place.

Search Console is the main source of evidence during this period. The Page indexing and Sitemaps reports show how quickly new URLs are being indexed and the URL Inspection tool shows how Google sees individual pages. Compare rankings, clicks and organic traffic with the pre-launch baseline section by section, so a problem in one area is not hidden by stable performance elsewhere.

Performance deserves the same attention, because new templates, scripts and plugins can change how quickly pages load and respond. Core Web Vitals measure loading with Largest Contentful Paint, responsiveness with Interaction to Next Paint (INP) and visual stability with Cumulative Layout Shift and the web.dev guidance recommends an LCP within 2.5 seconds, an INP of 200 milliseconds or less and a CLS of 0.1 or less. Check desktop and mobile separately against the scores recorded before launch.

AI search visibility is worth checking as well. Google says there are no additional requirements to appear in AI Overviews and AI Mode, but the same SEO fundamentals apply, including allowing crawling, making content findable through internal links and keeping structured data consistent with the visible text. A migration that breaks any of those can reduce how often your pages appear in AI answers as well as in traditional results.

Common Migration Mistakes That Cost Rankings

Most traffic losses after a migration trace back to a small number of avoidable mistakes. The four below come up most often and each one can be prevented with the checks set out above.

Changing too much at once is a mistake in its own right. A new domain, platform, URL structure and content set in one launch leaves no clear way to tell which change caused a drop, so phasing larger projects is often the safer route.

How Long Rankings Take to Settle After a Migration

There is no fixed recovery period after a migration and Google does not give one. Its site move documentation says that for medium-sized websites it can take a few weeks or more for Google to start showing the new URLs instead of the old ones and longer for larger websites.

The time it takes depends on the size of the website, how often Google crawls it and how cleanly the redirects and signals were handled. Google also recommends keeping redirects in place for as long as possible and generally for at least one year, so old links and bookmarks continue to pass visitors and signals to the new pages.

A traffic drop that continues well beyond the first few weeks usually points to a specific problem rather than normal fluctuation. Check the redirects on the affected pages first, then compare their content, internal links and indexing status with the pre-launch crawl.

When to Bring in Specialist Migration Support

Specialist help is worth considering when the website carries significant organic traffic, when the domain or platform is changing or when the project involves thousands of URLs. The same applies when your internal team or developer does not have the capacity to map, test and monitor the migration alongside the build itself.

Priority Pixels handles SEO migrations as part of its technical SEO services and specialises in WordPress migrations, including moves from other platforms to WordPress. Every migration client gets access to our reporting platform, which holds the pre-migration baseline alongside live data on indexation, redirect health and rankings for priority queries, with a monthly review call to walk through what has recovered and what still needs attention.

Migrations are often part of a bigger rebuild and the SEO work tends to run more smoothly when it is planned alongside the design and build. Our web design projects include 301 redirects in the testing phase and our WordPress support team tests updates on a staging copy before they reach the live website. For moves that only change hosting, our guide to WordPress hosting migration covers the steps involved.