Short answer: Before you move a shop, list every old URL and decide where each one goes on the new site. Send each old address to its closest match with a permanent server-side redirect, keep product structured data in place, submit a new sitemap and watch Search Console. Expect rankings to move around for a few weeks.
A shop that has been online for a few years has built something you can't see in the admin panel. Product pages that rank. Category pages other sites link to. Customers with old order emails that still point at product URLs. When you move to a new platform, all of that is attached to addresses, and new platforms like to change addresses.
Search traffic lost in a migration usually isn't lost because the new shop is worse. It's lost because the old URLs stopped leading anywhere. That part is preventable, and Google documents how.
Why do shops lose search traffic when they move?
To a search engine, a URL is the identity of a page. Everything it knows about your blue running shoe, its content, its links, its history, is filed under that address. Change the address without a forwarding note and the new page starts from nothing, while the old one returns an error and drops out.
Platforms differ in how they build URLs. One puts products under one path and another uses a different one. Category structures change. Filters and pagination behave differently. Even if every product makes the trip, almost every address may be new.
What should you do before the move?
1. Change one thing at a time
Google's guidance on site moves suggests not combining changes: move the platform, or change the domain, or redo the design, but not all in the same week. If traffic drops after you changed three things, you won't know which one did it. A new platform already means new templates, so if you can keep the domain and the content the same for the move, do.
2. Collect every old URL
Not just the ones in the menu. Google suggests building the list from several places: your sitemaps, server logs, analytics, the content management system and the links report in Search Console. On a shop that means products, categories, brand pages, blog posts, policy pages and, for larger shops, discontinued products that still get visits. Google's list also includes images, because product photos can bring visitors through image search.
3. Map each old URL to a new one
This is the core of the job. It's a spreadsheet with two columns: old address, new address. For most products the match is obvious. The decisions are in the rest:
- Discontinued products. Send them to the replacement product or the closest category.
- Merged categories. Send both old ones to the new one.
- Pages with no equivalent. Let them return a "not found" response. That is more honest than sending people somewhere unrelated.
What Google specifically warns against is redirecting lots of old URLs to one unrelated page, such as the new home page. It's the quickest thing to set up and it throws away most of what those pages had earned.
4. Prepare the new pages
Each new URL should have a canonical tag pointing to itself. Internal links, in menus, in product descriptions and in blog posts, should point straight at the new addresses and not rely on redirects. If the shop has language versions, the hreflang annotations need the new URLs too. And keep the things that made the old pages rank: titles, descriptions, the text on category pages. A migration is a bad moment to delete all the category copy because the new theme has no slot for it.
5. Carry over structured data
Product structured data is the markup that lets Google show price, availability and review ratings alongside your result. Google distinguishes two kinds: product snippets, and merchant listings for pages where people can actually buy the product. Your old platform or one of its plugins probably produced this markup without you thinking about it. The new one may not, or may produce it differently. Check a few product pages on the new shop before launch to confirm the markup is there and the price and availability in it match what the page shows.
6. Test on a staging copy
Build the new shop somewhere private and run the old URL list against the redirect rules before launch. Every old address should land on the right page in one step. Keep the staging copy out of search engines, and remember to remove that block when you go live. Google's guidance mentions the same thing: once the move is done, make sure any temporary noindex rules are gone.
What should you do on launch day?
- Use permanent, server-side redirects. Google recommends 301 or 308 where possible and calls permanent server-side redirects the best way to make sure both Google and people reach the right page. Meta refresh and JavaScript redirects are fallbacks for when you can't do it on the server.
- Avoid chains. Each old URL should go straight to its final destination, not through two or three hops.
- Submit a sitemap with the new URLs in Search Console.
- If the domain is changing, verify both the old and new sites in Search Console and use the Change of Address tool. You don't need it when only the paths change.
- Pick a quiet period if you can. Not the week of your biggest sale.
- Place a test order. It isn't an SEO step. It is still the most important check of the day.
What should you watch after the move?
Google's advice is to watch indexing and search queries for the new URLs in Search Console, and to check server logs and analytics for unexpected errors. In practice:
- The number of new URLs indexed should climb while the old ones fall.
- "Not found" errors show you what the mapping missed. Add those redirects as they turn up.
- Traffic to your main product and category pages should recover to roughly where it was.
- Where other sites link to old URLs, ask the important ones to update the link. The redirect covers it meanwhile.
How long does it take to settle?
Google says to expect rankings to fluctuate for a few weeks on a small or medium site, and longer on a large one, while it recrawls and reindexes everything. Some movement is normal and not a sign that something is broken. A steady decline on specific pages after the first few weeks is worth investigating.
Keep the redirects in place for as long as you can. Google's guidance says generally at least a year. Old links, bookmarks and order confirmation emails stay around longer than that, and a redirect costs nothing to keep. Nobody can promise that rankings come through a move untouched, but following the steps above removes the avoidable causes.
Sources
- Google Search Central, How to move a site, on URL mapping, redirects, sitemaps, Change of Address and monitoring.
- Google Search Central, Redirects and Google Search, on permanent and temporary redirects and which methods Google prefers.
- Google Search Central, Introduction to Product structured data, on product snippets and merchant listings.
Moving a shop from one platform to another is part of what we do. The e-commerce page explains how we approach it: we look at how your orders flow from the product page to the parcel, then plan the move around the pages customers and search engines already know. Or book a free call and tell us what you're moving from.