The story is always the same. The new store is better looking, faster, everyone is pleased. Three weeks later traffic has collapsed and orders with it. Nothing is broken: Google simply cannot find the pages it used to know.
What is actually happening
Your search visibility does not belong to your store, it belongs to your addresses. Every product page and every category has a URL that Google has indexed and attached a value to, sometimes built over years.
Each platform has its own way of building addresses. Changing platform therefore changes the URLs, often all of them. Without a plan every old address returns an error, and the accumulated value disappears with it.
The redirect plan comes before everything else
This is the one non negotiable step. The principle is simple: every old address must point to its closest equivalent on the new site, with a permanent redirect. That is what passes the value along.
In practice, before migrating:
- Export the full list of currently indexed addresses. Not just active products: categories, content pages, and discontinued products that still receive visits.
- Cross that list with your analytics and Search Console to spot the ones actually bringing traffic.
- Map each one to its destination on the new site.
- Handle the cases with no equivalent: a discontinued product redirects to its category, never to the homepage in bulk.
What else gets lost, and gets forgotten
Customer reviews. Often stored by a module tied to the platform, so not exported with the catalogue. They carry social proof that is hard to rebuild. Check they can be recovered before you start.
Carefully written descriptions. Automatic exports happily strip formatting, tables and embedded images. Check a representative sample, not just the first three products.
Structured data. Price, availability, reviews: these produce the rich results in search listings. They need reconfiguring on the new platform.
Order history. Needed for customer service and for your accounts. Plan its migration, or at minimum a usable archive.
Launch day
Switch during a quiet period of your trading year, not the day before a peak. Keep the old store reachable internally for a few weeks: it is your only recourse when a piece of data looks wrong.
On the day, in order: check the new site is indexable, which means removing the block used during preparation. That single forgotten line can deindex an entire store. Then submit the new sitemap, and manually test thirty or so of the most visited old addresses.
The following weeks
A dip in traffic in the first days is normal while redirects are processed. What is not normal is that dip persisting beyond a few weeks.
Watch the crawl errors reported in Search Console, the pages losing position, and conversion rate against the same period last year. A drop in conversion without a drop in traffic is not a search problem: look at the checkout instead.
The short version
A successful migration is won before launch. The redirect plan is most of the invisible work, and it is the first thing cut when the schedule tightens. It is precisely the thing not to cut.