Most BigCommerce-to-Shopify data migrations focus on moving products, customers, and order history. When you’re migrating from a platform that doesn’t scale or meet your ecommerce needs, data migration to Shopify can be critical for business growth.
But what happens when your data migration project doesn’t take into account your SEO and CRO work?
DIY tools and migration apps were built to transfer data, but they don’t consider the separate work of ensuring SEO and conversions remain intact throughout your move.
How do you preserve SEO and CRO during a BigCommerce to Shopify migration?
Preserving SEO and CRO during a BigCommerce to Shopify migration requires attention to SEO and CRO elements such as:
- A complete URL redirect strategy
- A pre-migration CRO audit to measure current performance
- Intentional rebuilds of high-converting products, pages, or category/collections
- Carry over on-page SEO elements like meta data and canonicals
- A strategy for low-performance content that shouldn’t migrate over
Whirlwind Ecommerce is a Shopify Preferred Partner. We’ve spent 20+ years supporting hundreds of ecommerce companies, and we know how important it is to preserve SEO and CRO during a migration project.
This is why we take a CRO-first approach to all of our client projects. If you’re considering a move from BigCommerce to Shopify, let’s talk.
What happens when SEO and CRO drop after a Shopify migration?
The stakes of a botched migration are high: lose 25-40% of organic traffic or see large conversion dips in the first 90 days, and it could take months to recover the lost sales.
Here's what breaks when a migration goes wrong:
- Organic rankings disappear because URLs changed and nothing redirected. Google treats the new pages as net-new content with no authority.
- Top-converting products and pages don’t get the attention they deserve.
- Trust signals don't carry over. Reviews, badges, FAQ content, and social proof have to be re-implemented on Shopify, and most migration projects don't budget for the time it takes to do that well.
- Page speed regressions hit Core Web Vitals and reduce both rankings and conversion.
- Tracking breaks.
The damage compounds as lost rankings reduce traffic and lost trust signals reduce conversion. Lost tracking means neither problem is visible quickly enough to fix.
Find out how long it takes to migrate from BigCommerce to Shopify.
Why do DIY migrations and apps fail to preserve SEO and CRO?
Migration apps move structured data. Products, customers, orders, and basic metadata transfer cleanly. They’re not designed to consider SEO equity and conversion elements, or have the ability or nuance to strategize through a complex catalog or your operational infrastructure.
You can treat SEO and CRO preservation as a post-launch fix-it project, but why leave sales on the table as an afterthought?
Specifically, migration apps don't:
- Audit top organic landing pages and confirm those URLs map to working 301 redirects
- Analyze which product page layouts drive the highest conversion rate and rebuild those layouts intentionally
- Review BigCommerce's filter and faceted navigation structure and replicate the SEO-friendly version on Shopify
- QA structured data, internal linking, or canonical tags after launch
- Validate that tracking pixels are firing on the right events
Data migration and conversion preservation are two different jobs that require two different methodologies.
What makes Whirlwind's BigCommerce to Shopify migrations different?
Whirlwind has been doing ecommerce since 1999. That's 27 years of platform changes, algorithm updates, and tested conversion patterns across hundreds of DTC brands. Our strategy team is 100% in-house, so migration projects stay with the same Whirlwind team from kickoff through post-launch.
Our average Shopify migration project retains 99.6% of the original site's conversion rate.
We track this on every project because moving a site without keeping the sales is the worst outcome for a Shopify migration project.
Every Whirlwind migration is approached as a CRO project that happens to involve a platform move. Preserving and improving sales is our goal. That methodology is what produces our client conversion lifts after launch. See our portfolio of client results.
How do you map URLs for a BigCommerce to Shopify migration?
URL mapping for a BigCommerce to Shopify migration requires a full crawl of the current site, an export of every URL with traffic or backlinks, a one-to-one match to its Shopify equivalent, and 301 redirects implemented before launch. Every URL that carries organic value needs a working redirect, including category, product, blog, and resource pages.
The redirects are what tell Google that a page has permanently moved and that link equity from the old URL should transfer. Without redirects, every backlink pointing to your BigCommerce site loses its value the moment Shopify goes live.
Test the redirect chain before launch and again after. A single redirect loop or broken chain can silently kill rankings on your highest-traffic pages.
What should you audit before migrating from BigCommerce to Shopify?
Before a BigCommerce to Shopify migration starts, audit the top performing organic landing pages by traffic and conversion, conversion rate by product page template, average order value by traffic source, top exit pages, page speed scores, and Core Web Vitals for the highest-traffic templates.
This baseline is what the new Shopify site gets measured against post-launch.
You can't preserve what you haven't measured. If a product page template was converting at 4.2% on BigCommerce and converts at 2.8% on Shopify, the baseline is what tells you something broke and where to look.
The audit also shows what's worth keeping. Not every page on the old site needs to come over. Some content should be consolidated, some should be retired, some should be redirected to a stronger page. The pre-migration audit is when those decisions get made with data and time to think them through.
How do you preserve conversion rate during a platform migration?
To preserve conversion rate during a Shopify migration, identify the pages driving the highest conversion before launch, document the specific elements making them work (layout, trust signals, copy, button placement, review display), and replicate those elements on Shopify. Then run side-by-side conversion comparisons after launch and fix what dropped.
When a product page converts well, the performance is built on specific elements: the order of content, placement of trust signals, the size and position of the add-to-cart button, the way reviews are displayed, urgency cues, shipping messaging.
A developer rebuilding the same page on Shopify without that context will rebuild it however they normally build product pages. The result is often a worse layout that the brand didn't ask for and didn't notice until conversion dropped.
Documentation is critical to this process. Before the build starts, identify the templates carrying the most conversion weight. Document, replicate, and validate throughout the process.
What technical SEO elements need to transfer to Shopify?
A complete technical SEO transfer to Shopify includes page titles and meta descriptions, structured data (product, FAQ, organization, breadcrumb), image alt text and filenames, internal linking structure, canonical tags, robots.txt directives, XML sitemap structure, tags for international sites, and Open Graph metadata.
Missing any of these can lead to drops in traffic or sales in the first 90 days.
Together, gaps in these elements compound into an organic decline that can take 6 to 9 months to recover.
The mistake most teams make is assuming Shopify's defaults are enough. Shopify auto-generates some metadata, but the auto-generated versions rarely match the optimized versions an SEO-aware team built on BigCommerce.
How do you validate SEO and CRO after a Shopify migration goes live?
Post-launch validation of a BigCommerce to Shopify migration compares the first 30 days of conversion rate by template, organic impressions and clicks for top-ranking pages, Core Web Vitals scores, tracking event firing across GA4 and Meta, cart abandonment, and checkout completion against pre-migration baselines.
The optimal window for finding and fixing migration issues is the first 30 days, before seasonal patterns and other variables make attribution harder.
Specifically, compare:
- Conversion rate by template, by traffic source, by device against pre-migration numbers
- Organic impressions and clicks in Search Console for top-ranking pages
- Core Web Vitals scores on highest-traffic templates
- Tracking events firing across GA4, Meta pixel, and email platform
- Cart abandonment and checkout completion rates
If something dropped, it gets found in week one or two while the data is still clean enough to act on.
Ready to migrate from BigCommerce to Shopify without losing what you've built?
A BigCommerce to Shopify migration is two distinct workstreams: data migration and SEO/CRO preservation. Most agencies handle the first one and treat the second as optional. Whirlwind treats both as core scope.
Whirlwind runs Shopify migrations for DTC brands doing $5M to $100M in annual revenue. Our 99.6% conversion retention number is what we measure against, and we walk clients through the specific risks and protections in the first call.
Book a strategy call and we'll walk through what's involved with migrating your specific store: traffic patterns, conversion data, timeline, and what preserving your SEO and CRO would look like in practice and provide a quote for how much it costs to migrate from BigCommerce to Shopify.