An ecommerce migration is one of the highest-stakes projects a brand can undertake. Get it right, and you unlock better performance, lower costs, and a platform that grows with your business. Get it wrong, and you lose organic traffic, break customer accounts, disrupt integrations, and potentially cost yourself hundreds of thousands in revenue during the recovery period.

We have managed migrations from every major platform — Magento, WooCommerce, OpenCart, Prestashop, BigCommerce, Squarespace, and bespoke systems — to Shopify and Shopify Plus. The patterns of success and failure are remarkably consistent. Success comes from thorough planning. Failure comes from cutting corners.

This checklist covers everything. Print it, share it with your team, and use it as a working document throughout your migration. Every item exists because we have seen what happens when it is skipped.

Why ecommerce migrations fail

Before the checklist, let us understand why migrations go wrong. The reasons are predictable and preventable.

Inadequate redirect mapping. This is the number one cause of migration failure. When URLs change between platforms (and they almost always do), every old URL needs a 301 redirect to its new equivalent. Miss one high-traffic URL and you lose that organic traffic — potentially permanently. For a store with 500 products, 40 collections, and 30 blog posts, that is 570+ redirects that need to be created and tested individually.

Data corruption during transfer. Product data, customer records, and order history can be corrupted during migration if the data formats between platforms are not compatible. Prices that lose decimal places, product variants that map incorrectly, customer addresses that truncate — these are not edge cases. They happen in the majority of migrations that do not have proper data validation.

Integration gaps. Your current store connects to various third-party systems — fulfilment, accounting, email marketing, reviews, ERP. Each integration needs a Shopify equivalent, and each needs to be configured and tested before launch. Discovering on launch day that orders are not reaching your fulfilment centre is a preventable disaster.

Underestimating SEO complexity. As we cover in our guide on the true cost of legacy platforms, the organic traffic you have built over years is one of your most valuable assets. A migration that does not prioritise SEO preservation can destroy that asset overnight.

Pre-migration: audit and planning

The pre-migration phase is where most of the value is created. Every hour spent in planning saves multiple hours in execution and recovery.

Current store audit

  • Crawl your existing site. Use Screaming Frog or Sitebulb to create a complete inventory of every URL on your current site. Export this data — you will use it for redirect mapping. Record the URL, page title, meta description, H1, word count, and HTTP status code for every page.
  • Export Google Analytics data. Download at least 12 months of traffic data, broken down by page. You need to know which pages drive the most organic traffic and revenue so you can prioritise their migration. Export the landing page report, organic revenue by page, and conversion rate by page.
  • Export Google Search Console data. Download your search performance data (queries and pages), external links report, and any manual actions or security issues. This data is tied to your domain and will persist through the migration, but having a pre-migration baseline is essential.
  • Document your current URL structure. Map out the URL patterns for products, collections, blog posts, and content pages. For example: /product/blue-widget on WooCommerce becomes /products/blue-widget on Shopify. Understanding these pattern differences is critical for redirect mapping.
  • Inventory all integrations. List every third-party tool connected to your current store: payment gateways, shipping providers, fulfilment centres, email marketing (Klaviyo, Mailchimp, etc.), review platforms, analytics, accounting, ERP, and customer service tools. For each one, note how it connects (API, plugin, manual), what data flows between systems, and whether a Shopify equivalent exists.

Goal setting

Define what success looks like before you start. Typical migration goals for brands we work with include matching or exceeding current organic traffic within 8 weeks, zero data loss (all products, customers, and orders migrated accurately), all integrations functioning correctly from day one, improved site speed (targeting 90+ mobile PageSpeed), and improved mobile conversion rate.

Document these goals and share them with your agency. They form the benchmarks against which you will measure the migration's success.

SEO preservation checklist

This is the most critical section. SEO preservation is the difference between a migration that maintains your revenue and one that decimates it.

URL mapping and redirects

// Common URL pattern changes in migration
const urlChanges = {
  // WooCommerce to Shopify
  '/product/':        '/products/',
  '/product-category/': '/collections/',
  '/shop/':           '/collections/all',

  // Magento to Shopify
  '/catalog/product/': '/products/',
  '/catalog/category/': '/collections/',
  '.html':             '', // Magento uses .html extensions

  // Custom platforms
  // Every URL needs individual mapping
};
  • Create a complete redirect map. Every URL on your current site needs a corresponding destination on the new site. This is not optional. Export your crawl data and create a spreadsheet with old URL, new URL, and redirect type (301 permanent) for every page.
  • Prioritise by traffic. Start with your highest-traffic pages. If you have 2,000 URLs but only 200 drive meaningful traffic, get those 200 perfect first. Then handle the rest.
  • Handle parameter URLs. Many platforms generate URLs with parameters (e.g., ?sort=price&page=2). These often get indexed by Google and need handling in the redirect map.
  • Plan for image URLs. Product images often change URLs during migration. If external sites link to your images, those links will break. Map image URLs if they are linked externally.
  • Test every redirect. Before launch, test a sample of redirects manually. After launch, crawl the site and verify that 301 redirects are working correctly — not 302s (temporary), not redirect chains, and not 404s.

On-page SEO preservation

  • Migrate title tags and meta descriptions. Export all title tags and meta descriptions from your current site and import them into the new one. Do not let your new platform auto-generate these — you will lose years of optimisation.
  • Preserve heading structure. Ensure H1 tags, H2s, and content structure are maintained on the new site. If you are redesigning, make sure the new design includes the same keyword-rich headings.
  • Maintain internal linking. Internal links are part of your SEO equity. If your blog posts link to product pages using old URLs, those links need updating to the new URLs (or the redirects need to handle them).
  • Implement structured data. If your current site has Product schema, BreadcrumbList, and other structured data, ensure the new site maintains or improves it. Shopify handles some schema natively, but most stores need additional implementation.
  • Preserve canonical tags. Ensure canonical tags are correctly implemented on the new site to prevent duplicate content issues.
  • Submit updated sitemap. After launch, submit the new XML sitemap to Google Search Console and request indexing for your key pages.

Data migration checklist

Data migration is where precision matters. Small errors compound across thousands of records.

Product data

  • Export all product data. Titles, descriptions, images, prices, variants (size, colour, etc.), SKUs, barcodes, weights, SEO fields (title tag, meta description, URL handle), tags, and collections/categories.
  • Map product variants. Different platforms handle variants differently. WooCommerce uses variable products with attributes. Shopify uses up to 3 option fields with 100 variant combinations. If your current setup exceeds Shopify's variant limits, you need a plan (product bundling, metafields, or custom solutions).
  • Validate data formats. Prices need correct decimal formatting. Weights need consistent units (kg or g). Image files need accessible URLs. HTML in descriptions needs to be compatible with Shopify's rich text editor.
  • Migrate product images. Ensure all product images are migrated at their original quality. Compressed or missing images reduce trust and conversion rate. Verify image alt text is preserved.
  • Test with a sample. Before migrating all products, import 20–30 representative products and verify everything displays correctly. Check variants, pricing, images, descriptions, and SEO fields.

Customer data

  • Export customer records. Names, email addresses, phone numbers, addresses, order history, tags, and marketing consent status.
  • Handle GDPR compliance. You can only migrate customer data if you have a lawful basis for processing it. For most ecommerce brands, this is covered by legitimate interest (processing past orders) or consent (marketing). Ensure marketing opt-in status is accurately migrated.
  • Plan for password resets. Customer passwords cannot be migrated between platforms. Plan a communication strategy to notify customers that they will need to set a new password. Shopify provides account invitation emails for this purpose.
  • Migrate order history. Past orders should be migrated so customers can view their purchase history in their account. This data is also valuable for email marketing segmentation — customers with high lifetime value, repeat purchasers, and lapsed customers can be targeted differently.

Content migration

  • Blog posts. Migrate all blog content with original publication dates, author information, and URL structures preserved where possible.
  • Static pages. About, contact, FAQ, shipping policy, returns policy, privacy policy, and terms of service all need migrating. Review and update them during the migration — many brands have outdated policy pages.
  • Collection/category descriptions. These are often overlooked but are important for SEO. Migrate all collection descriptions and optimise them during the process.

Integration mapping

Every integration is a potential failure point. Map them all and test them all before launch.

Integration type What to check Common issues
Payment gateways Gateway available on Shopify, test transactions work Different gateway providers, subscription payment continuity
Shipping/fulfilment Order data flows correctly, shipping rates match API changes, rate calculation differences
Email marketing Customer data syncs, automations trigger Data mapping, flow rebuild in Klaviyo
Reviews Existing reviews migrate, new reviews collect Review data format, star rating mapping
ERP/accounting Orders, inventory, and financial data sync API differences, field mapping
Analytics GA4, GTM, conversion tracking configured Data layer implementation, enhanced ecommerce

For each integration, test the complete data flow end-to-end before launch. Place a test order and verify it reaches your fulfilment centre, triggers the correct email flows, appears in your accounting system, and records correctly in analytics.

Design and build phase

The design and build phase runs in parallel with data migration planning. For a detailed breakdown of build timelines, see our guide on how long a Shopify build should take.

Design considerations for migration

  • Preserve navigation patterns. Customers expect to find things where they left them. Major changes to navigation structure can disrupt returning customers. Evolve rather than revolutionise.
  • Maintain brand consistency. A migration is not the time for a complete rebrand unless that is explicitly part of the scope. Returning customers should recognise the store.
  • Improve mobile experience. If your legacy platform had poor mobile performance, the migration is your opportunity to fix it. Prioritise mobile-first design and development.
  • Optimise for performance. Target 90+ on mobile PageSpeed from day one. This means careful image optimisation, minimal app installation, and efficient theme code.

Build checklist

  • Theme development (custom or customised)
  • Shopify configuration (shipping zones, tax rules, payment providers)
  • App installation and configuration (minimal — only what is essential)
  • Custom functionality development
  • Content integration and formatting
  • Redirect implementation
  • Analytics and tracking setup

Testing and QA checklist

Test everything. Then test it again. The cost of finding a bug in testing is a fraction of the cost of finding it in production.

Functional testing

  • Product pages display correctly (images, variants, pricing, descriptions)
  • Add to cart works for all product types (simple, variant, subscription)
  • Cart functions (update quantity, remove items, apply discount codes)
  • Checkout flow completes (guest checkout and logged-in)
  • Payment processing works (test transactions with every enabled gateway)
  • Shipping rates calculate correctly for all destinations
  • Tax applies correctly (VAT for UK, exemptions where applicable)
  • Order confirmation email sends with correct information
  • Customer account creation and login work
  • Search returns relevant results
  • Filtering and sorting work on collection pages
  • Forms submit correctly (contact, newsletter signup)

Cross-browser and device testing

  • Chrome, Firefox, Safari, Edge on desktop
  • iOS Safari and Chrome on iPhone
  • Android Chrome on multiple screen sizes
  • Tablet testing (iPad, Android tablets)

SEO testing

  • All redirects return 301 status (not 302)
  • No redirect chains (A redirects to B redirects to C)
  • Title tags and meta descriptions are correct on all pages
  • Canonical tags are correct
  • XML sitemap is generated and accurate
  • robots.txt allows appropriate crawling
  • Structured data validates in Google's Rich Results Test
  • No broken internal links

Performance testing

  • Mobile PageSpeed score of 90+ on key page types
  • Core Web Vitals pass on homepage, collection page, and product page
  • Images are optimised and lazy-loaded
  • No render-blocking resources in the critical path

Launch day checklist

Launch day should be boring. If you have done the preparation correctly, it is a straightforward DNS switch and monitoring exercise.

Pre-launch (morning of launch)

  1. Final data sync — ensure any products or orders created since the last migration are captured
  2. Enable password protection on the new store (if not already live)
  3. Final redirect verification on a sample of high-traffic URLs
  4. Confirm all integrations are switched to production mode (not sandbox)
  5. Notify your team — customer service, fulfilment, marketing

Launch execution

  1. Update DNS records to point to Shopify
  2. Remove password protection from the new store
  3. Verify SSL certificate is active (Shopify provisions automatically, but verify)
  4. Place a real test order and verify the complete flow
  5. Check that Google Analytics is receiving data
  6. Submit updated sitemap to Google Search Console
  7. Test all payment gateways with real transactions (refund the test orders)

Timing considerations

Launch on a Tuesday or Wednesday morning. Never launch on a Friday (you do not want to discover problems over the weekend). Avoid launching during peak sales periods, promotional campaigns, or immediately before a holiday. DNS propagation can take up to 48 hours, so plan for a transition period.

Post-launch monitoring

The first 30 days after launch are critical. Monitor everything closely and be prepared to fix issues quickly.

Week 1: intensive monitoring

  • Monitor Google Search Console for crawl errors daily
  • Check organic traffic in analytics daily — compare to the same day the previous year
  • Verify orders are flowing to fulfilment correctly
  • Monitor customer service for migration-related complaints
  • Check for broken redirects (crawl the old URL list and verify 301 responses)
  • Monitor site speed — new apps and integrations can degrade performance

Weeks 2–4: stabilisation

  • Review organic ranking trends for key terms
  • Fix any remaining redirect issues
  • Optimise any pages with performance issues
  • Request indexing for key pages that are not appearing in search results
  • Begin optimisation work — the new store is a fresh canvas for CRO improvements

Month 2–3: recovery and growth

  • Organic traffic should be recovering to pre-migration levels
  • Address any lingering 404 errors in GSC
  • Begin content creation on the new platform
  • Implement CRO improvements based on the new platform's data
  • Review integration performance and optimise data flows

A migration is not complete when the new store goes live. It is complete when your organic traffic has recovered, your integrations are stable, and your conversion rate exceeds the old store. That typically takes 8–12 weeks of post-launch work.

Andrew Simpson, Founder

What to do if organic traffic drops significantly

Some temporary traffic fluctuation is normal. But if organic traffic drops by more than 20% and does not begin recovering within two weeks, take these steps immediately: verify all redirects are working (crawl the old URL list), check Google Search Console for manual actions or security issues, confirm the XML sitemap is submitted and being processed, check for accidental noindex tags on key pages, verify canonical tags are not pointing to the old domain, and check that the robots.txt file is not blocking important pages.

If you are working with an agency that handles both Shopify development and SEO, they should be monitoring all of this proactively. You should not be discovering these issues yourself. Our guide to choosing the right Shopify agency covers what to look for in an agency that can handle migrations properly.

For brands still weighing whether to migrate at all, our analysis of the true cost of staying on a legacy platform puts hard numbers to the decision. And for those who want to understand the build timeline, our Shopify build timeline guide covers exactly what to expect.

An ecommerce migration is a significant undertaking, but it is not complicated if you follow the process. Every item on this checklist exists because we have seen what happens when it is skipped. Follow it methodically, and your migration will be smooth, your traffic will recover, and your new store will outperform the old one.

If you are planning a migration and want expert guidance, talk to us. We have managed migrations for brands across every major platform, and we will give you an honest assessment of scope, timeline, and cost. No surprises.