A site migration, whether that's a full replatform (moving from Magento to Shopify, for example), a domain change, or simply a large-scale URL structure change, is one of the highest-risk moments in an ecommerce site's SEO history. Migrations go wrong often enough, and the traffic loss is severe enough when they do, that this deserves a structured process rather than an assumption that "the developer will handle redirects."
Why Migrations Are High Risk
Search engines rank URLs, and everything a URL has accumulated (backlinks, historical performance, indexing history) is tied to that specific address. Change the URL structure, the domain, or the platform without carefully preserving that history, and you're effectively asking search engines to evaluate thousands of pages as brand new, with no track record, all at once. Rankings built up over years can drop within days if this isn't handled correctly, and recovery, if it happens at all, can take months.
Before the Migration: Planning
Full Site Crawl and URL Inventory
Before anything moves, crawl the existing site to produce a complete list of every indexable URL, along with its current organic traffic, backlinks, and ranking keywords. This becomes the baseline you'll measure recovery against, and it's also the source list for redirect mapping.
Redirect Mapping
Every old URL that has any organic value needs a 301 redirect to its most relevant equivalent on the new site. "Most relevant" matters: a blanket redirect of every old URL to the new homepage, sometimes called a "redirect everything to home" shortcut, tells search engines nothing useful and typically causes a bigger traffic loss than doing no redirects at all. Product-to-product, category-to-category mapping, done manually or via a careful matching script for large catalogues, is the standard that protects rankings.
Preserve On-Page SEO Elements Deliberately
A replatform is often also treated as an opportunity to "refresh" content, titles, and URLs all at once. Resist doing all three simultaneously. Changing URL structure, page content, and technical setup in the same migration makes it far harder to diagnose what caused any post-launch ranking movement, because there are too many variables changing at once. Where possible, separate a platform migration from a content or URL structure overhaul into two distinct projects, done a reasonable interval apart.
At Launch
- Update the XML sitemap to reflect only the new, live URLs, and submit it in Search Console immediately.
- Check robots.txt on the new site carefully. A disturbing number of migrations accidentally launch with
Disallow: /left over from a staging environment, blocking the entire site from being crawled. - Verify redirects are actually live by spot-checking a sample of high-value URLs manually, not just trusting that the redirect map was implemented as specified.
- Re-verify Search Console and Analytics are correctly installed and tracking on the new platform, since tracking code is easy to lose in a platform change.
After Launch: Monitoring
Expect some ranking volatility in the first two to four weeks even in a well-executed migration; this is normal as search engines re-crawl and re-evaluate the new URLs. What matters is the trend, not day-to-day noise. Monitor:
- Indexing status in Search Console, checking that the new URLs are being indexed at a similar or better rate than the old ones were.
- Organic traffic and rankings for your priority keyword and page list, compared against the pre-migration baseline.
- Crawl errors and redirect chains, since redirects that point to other redirects (chains) rather than directly to the final URL waste crawl budget and slow down how quickly search engines process the change.
If a significant, unexplained drop appears after the initial settling period, the most common causes are a missed redirect on high-value URLs, an accidental robots.txt or noindex issue, or a technical problem (broken canonical tags, missing structured data) introduced during the platform change rather than anything algorithmic.
Being Honest About Timelines
We won't claim a specific recovery timeline as if it's guaranteed, because no two migrations are identical. What we can say, based on migration behaviour across ecommerce sites generally, is that a well-planned migration with complete redirect mapping typically shows most of its recovery within four to eight weeks, while a poorly planned one can take considerably longer and sometimes never fully recovers the pages that were mishandled.
Update, 9 October 2026: After a migration, use the Generative AI performance report alongside the standard reports to check your key pages still appear, and wait for core update rollouts to finish before judging results (see the 2026 core updates).