9 Out of 10 Website Migrations Damage SEO—Here's How to Avoid Losing 50% of Your Traffic

Only 1 in 10 website migrations result in improved search engine rankings.

Nine out of ten fail. They damage SEO, lose organic traffic, and waste tens of thousands of pounds. One large retailer lost approximately £3.8 million in the first month (roughly $5M USD) when their IT consultants rejected URL redirect recommendations during a £7.6 million+ redesign.

Your £25,000 website investment could cost you 50% of your organic traffic—or it could 5x it. The difference comes down to planning, not luck.

The brutal statistics:

• Average 523 days to recover pre-migration organic traffic levels
• 17% of sites never recover even after 1,000 days
• 50%+ traffic loss is common without proper SEO strategy
• Only 10% of migrations improve rankings

But here's the opportunity: companies that execute migrations properly see traffic increases of 5x or more. HireRoad's multi-domain migration exceeded traffic expectations by 14.5% one year after launch—and traffic never dipped below anticipated levels.

We've guided dozens of UK businesses through platform changes, redesigns, and domain migrations over 15+ years. The pattern is consistent: proper pre-migration planning, comprehensive redirect mapping, and structured 90-day post-launch monitoring determine success or failure. Most agencies focus on aesthetics and launch deadlines. We focus on protecting the organic traffic you've spent years building.

The Migration Failure Crisis

First, the scale of the problem.

Recovery Timeline Data

Search Engine Journal's analysis of 892 migrations provides the most comprehensive dataset:

Average recovery time: 523 days (nearly 18 months)

• Fastest recovery: 19 days (exceptional planning and execution)
• 17% of sites: Never recovered traffic even after 1,000 days
• 42% of sites: Never recovered traffic in an earlier study of 171 migrations

Nearly half of all migrations result in permanent traffic loss. You invest £12,000-£60,000 in a new website and lose half your organic traffic forever.

Expected Traffic Loss Ranges

Duplicator's SEO migration research shows expected traffic drops by migration type:

Light updates (design changes, minor UX improvements):

• Expected drop: 10-25%
• Recovery time: 4-8 weeks with proper planning

Large migrations (CMS change, platform switch, major restructure):

• Expected drop: 30-60%
• Recovery time: 4-12 months

Domain migrations (changing your actual domain name):

• Expected drop: 40-70%
• Recovery time: 6-18 months
• Highest risk category

Even well-executed migrations see at least a 10% temporary decrease in search performance during the weeks immediately following launch. This is normal. The question isn't whether you'll see impact—it's whether the impact is temporary and manageable or permanent and catastrophic.

Success Stories

Shopping mall website migration: Not only maintained but increased organic traffic by 5x post-relocation through comprehensive SEO migration strategy.

HireRoad multi-domain migration: Merged three domains into one unified domain whilst simultaneously rebranding. One year after migration, traffic exceeded expectations by 14.5% and never dipped below anticipated levels. They tested almost 1,000 strategic redirects before launch.

Source: Elk HQ migration impact analysis, Profound Strategy case study

The difference: Successful migrations plan for SEO from day one, not as an afterthought three weeks before launch.

Critical Failure Points

1. Improper 301 Redirects (Most Common Cause)

301 redirects are the single most important technical element of any migration. Get them wrong and you'll lose traffic immediately.

The £3.8M mistake: A large retailer planned a comprehensive website redesign. SEO consultants provided detailed redirect recommendations mapping old URLs to new URLs. IT consultants rejected the recommendations as "too complex" and implemented simplified redirects instead.

Result: The retailer lost approximately £3.8 million in first-month revenue from organic traffic collapse.

Source: iPullRank website migration guide

The Redirect Rules

1. Use Only 301 Redirects (Permanent)

• 301: Permanent redirect, passes ~90-99% of link equity
• 302: Temporary redirect, passes limited link equity
• 307: Temporary redirect (HTTP/1.1)

Never use 302 or 307 for migrations. Search engines interpret these as temporary—they won't transfer authority to the new URLs. Using the wrong redirect type costs you link equity and rankings.

2. Create 1:1 Mapping Every important old URL should redirect to the most relevant new URL. Don't redirect everything to the homepage.

Bad:

olddomain.com/services/web-design → newdomain.com
olddomain.com/services/seo → newdomain.com
olddomain.com/about → newdomain.com

Good:

olddomain.com/services/web-design → newdomain.com/services/web-design
olddomain.com/services/seo → newdomain.com/services/seo
olddomain.com/about → newdomain.com/about-us

3. Avoid Redirect Chains Each redirect adds latency and loses link equity. Don't create chains:

olddomain.com/page → newdomain.com/temp → newdomain.com/final

Direct redirect:

olddomain.com/page → newdomain.com/final

4. Mind Redirect Relevance GSQI's soft 404 case study shows what happens when relevance fails:

Clients redirected older product pages to less-relevant category pages or the homepage. Google Search Console sent soft 404 warnings (treating the redirects as deleted pages because content relevance was too low). Rankings and traffic dropped quickly.

The fix: Match old content to new content with similar intent, topic, and value. If you can't find a relevant new page, consider keeping the old content rather than forcing a poor redirect.

2. Lost or Missing Redirects

Missing redirects create 404 errors. Every 404 is a lost ranking, lost link equity, and lost traffic.

Common scenarios:

• Old blog posts not redirected to new blog structure
• Service pages with changed URLs, no redirects mapped
• Location pages deleted without redirects
• PDF resources, images, and downloadable content forgotten

Our redirect process:

1. Crawl entire old site with Screaming Frog
2. Export full URL list (typically 500-5,000 URLs for SME sites)
3. Map each URL to new equivalent
4. Prioritise high-traffic and high-authority pages
5. Test redirects on staging before launch
6. Verify every redirect post-launch

Yes, this is tedious. Yes, it's essential. The £3.8M loss case study happened because someone decided redirect mapping was "too complex" to do properly.

3. Slow Page Load Times

Migration is an opportunity to improve performance or accidentally destroy it.

The risk: New platforms often have different performance characteristics. WordPress to Shopify, for example, might introduce heavier JavaScript, slower server response times, or unoptimised images.

Core Web Vitals directly impact rankings. If your new site loads slower than your old site, you'll lose rankings even with perfect redirects.

Monitor these metrics before and after migration:

• Largest Contentful Paint (LCP): Should be under 2.5 seconds
• Interaction to Next Paint (INP): Should be under 200ms
• Cumulative Layout Shift (CLS): Should be under 0.1

Source: Alecan Marketing migration impact analysis

4. Missing Technical SEO Elements

Critical elements often lost during migration:

Canonical tags: Tell search engines which version of duplicate content is preferred. Without these, you risk duplicate content penalties.

Meta titles and descriptions: Custom-written metadata optimised for click-through rates. Generic templates destroy performance.

Heading structure (H1-H6): Proper semantic HTML hierarchy helps search engines understand content structure. Losing this degrades rankings.

Structured data (Schema.org): Particularly critical for AI search optimisation. ChatGPT, Perplexity, and Google AI Overviews rely heavily on structured data.

Internal linking architecture: The way pages link to each other distributes authority. Rebuilding a site without preserving internal link structure loses this distribution.

robots.txt: Controls what search engines can crawl. Accidentally blocking important sections is more common than you'd think.

XML sitemap: Updated sitemap showing new URL structure. Submit to Search Console immediately post-launch.

Source: Search Engine Land migration checklist

Platform-Specific Migration: WordPress to Shopify

WordPress to Shopify is one of the most common UK business migrations—and one of the riskiest for SEO.

The Challenges

URL structure changes: Shopify enforces specific URL patterns:

• Products: /products/product-name
• Collections: /collections/collection-name
• Pages: /pages/page-name
• Blog posts: /blogs/blog-name/post-title

If your WordPress URLs don't match this structure, you'll need comprehensive redirects.

Example:

WordPress: yoursite.com/shop/product-category/product-name
Shopify:   yoursite.com/products/product-name

Every single product and category URL requires a redirect.

50%+ traffic loss without proper planning is common for WordPress to Shopify migrations, according to LitExtension's Shopify SEO migration guide.

Critical WordPress to Shopify Best Practices

1. Map Every WordPress URL to Shopify Equivalent

Export all WordPress URLs using a plugin like Export All URLs or a site crawler. Create a spreadsheet:

Old WordPress URL	New Shopify URL	Priority
/shop/category/item-1	/products/item-1	High
/shop/category/item-2	/products/item-2	High
/about-us	/pages/about	Medium
/blog/post-title	/blogs/news/post-title	Medium

Priority levels:

• High: Product pages, high-traffic blog posts, pages with backlinks
• Medium: Category pages, standard informational pages
• Low: Admin pages, thank you pages, low-traffic content

2. Implement Redirects in Shopify

Shopify's redirect system (Settings > URL redirects) allows bulk import via CSV. Format:

Redirect from,Redirect to
/shop/category/item-1,/products/item-1
/shop/category/item-2,/products/item-2

For complex redirect needs, use Shopify apps like "Redirect Manager" or custom Liquid code in your theme.

3. Preserve Meta Titles and Descriptions

WordPress SEO plugins (Yoast, Rank Math, All in One SEO) store custom metadata. Export this before migration.

Shopify's native SEO fields are basic. You'll need to manually transfer:

• Product meta titles and descriptions
• Collection meta titles and descriptions
• Page meta titles and descriptions
• Blog post meta titles and descriptions

Yes, this is manual work for hundreds or thousands of items. Yes, it's essential. Generic "Product Name | Shop Name" titles destroy click-through rates. Each of these technical steps protects the organic traffic you've built.

4. Migrate Structured Data

WordPress plugins often handle structured data automatically:

• WooCommerce: Adds Product schema
• Yoast: Adds Article, Organization, and breadcrumb schema
• Schema Pro: Adds comprehensive schema types

Shopify's default schema implementation is basic. You'll likely need to:

• Add custom JSON-LD schema to product templates
• Implement Review schema (if you have reviews)
• Add FAQ schema to relevant pages
• Preserve breadcrumb schema

This is particularly important for 2025. AI search engines like ChatGPT and Perplexity rely heavily on structured data to understand and surface your products.

5. Maintain Performance

WordPress with good caching can be very fast. Shopify is generally fast out of the box, but:

• Heavy themes degrade performance
• Too many apps add bloat
• Unoptimised images kill load times
• Third-party scripts slow interaction time

Benchmark WordPress site performance before migration. Ensure Shopify performance matches or exceeds it.

Source: Meetanshi Shopify migration best practices, Search Engine Journal Shopify migration

Potential Opportunities

When executed properly, WordPress to Shopify migration can actually improve SEO:

Performance improvements: Shopify's global CDN and optimised infrastructure can increase page speed, improving Core Web Vitals and rankings.

Better mobile experience: Shopify's mobile-first themes often outperform WordPress themes on mobile devices.

Structured data by default: Modern Shopify themes include better default structured data than many WordPress themes.

Simplified technical SEO: Less to break, fewer plugins to maintain, automatic updates.

But these benefits only materialise with proper migration planning. Rush it and you'll lose traffic. Plan it and you'll gain competitive advantage.

Redesign vs. Rebuild: The Decision Framework

Not every project requires a full migration. Sometimes a redesign (keeping your CMS and URLs) is smarter than a rebuild (changing platforms).

Definitions

Redesign:

• Changes how the website looks and feels
• Updates layout, branding, UX, accessibility
• CMS and codebase remain mostly the same
• URLs typically stay the same
• Lower SEO risk

Rebuild:

• Replaces website's structure and technology
• New platform, modernised codebase, rearchitected backend
• URLs often change
• Higher SEO risk but potentially higher reward

Source: Socialectric redesign or rebuild guide

When to Choose Redesign

Indicators:

• Current site functions adequately
• No major technical issues (security, performance, scalability)
• Want to refresh appearance without platform risk
• Budget is limited (£3,000-£10,000 range)
• Timeline is tight (4-8 weeks)

Example scenario: Your WordPress site works fine. You just want modern design, better mobile responsiveness, and improved accessibility. A redesign using your existing WordPress installation makes sense.

SEO impact: Minimal if URLs stay the same. You're changing presentation, not structure.

When to Choose Rebuild

Indicators:

• Built on outdated technology (old PHP versions, unsupported CMS)
• Security vulnerabilities that can't be patched
• Performance problems that can't be solved without platform change
• Scalability limitations preventing growth
• Spending more time maintaining than improving

Example scenario: Your custom-built 2015 website runs on PHP 5.6 (unsupported and insecure). It's slow, doesn't work properly on mobile, and adding features requires expensive custom development. A rebuild on modern infrastructure (Next.js, headless CMS) makes sense—which offers 61% ROI increases and 58% time savings on project delivery with headless CMS.

SEO impact: High risk but necessary. The existing site will eventually fail anyway. Better to migrate strategically than wait for crisis.

UK Cost Considerations (2025)

Redesign costs:

• Cosmetic redesigns: £3,000-£10,000
• Substantial redesigns (UX improvements, accessibility upgrades): £10,000-£25,000

Rebuild costs:

• Standard rebuilds (WordPress to modern WordPress, or to Shopify): £12,000-£35,000
• Complex rebuilds (headless CMS, custom platforms, enterprise requirements): £35,000-£60,000+

Source: Socialectric pricing research, WebFX 2025 data. For comprehensive UK pricing context, see our complete 2025 web development cost guide which breaks down hidden fees and long-term ROI impact.

ROI consideration:

• Redesign: Lower upfront cost, faster delivery, lower SEO risk
• Rebuild: Higher upfront cost, longer timeline, but solves fundamental technical debt and positions for growth

For our clients, we typically recommend rebuilds when technical debt exceeds 40% of development budget. If you're spending nearly half your resources on maintenance, fixes, and security patches rather than growth initiatives, it's time to rebuild.

Hybrid Approach

You don't always have to choose. Redesign front-end whilst selectively rebuilding core components delivers value without full migration risk.

Example:

• Keep WordPress CMS (familiar, works, has SEO history)
• Rebuild front-end using headless architecture for performance
• Modernise critical components (checkout, search, forms)
• Leave low-risk pages as-is

This approach balances innovation against risk. You improve where improvement matters whilst preserving what already works.

Pre-Migration Planning Checklist

Successful migrations start weeks before any code changes.

Step 1: Full Site Backup

Before touching anything:

• Complete database backup
• Full file system backup
• Export all content
• Document current configuration

This isn't paranoia—it's insurance. If migration goes sideways, you need a rollback option.

Step 2: Create Staging Environment

Never migrate directly on production.

Set up a staging site that mirrors production:

• Same content
• Same URLs
• Same plugins/apps
• Different domain (staging.yoursite.com or similar)

Test the entire migration on staging first. Fix issues before they impact live traffic.

Step 3: Crawl Current Site

Use Screaming Frog, Sitebulb, or similar crawler to document current state:

Essential data to export:

• All URLs (pages, posts, products, categories, images, PDFs)
• Response codes (200, 301, 404)
• Meta titles and descriptions
• H1 tags
• Canonical tags
• Structured data present
• Internal link structure
• Page load times
• Word counts

This becomes your baseline. Post-migration, you'll crawl again and compare. Any discrepancies need fixing.

Step 4: Document Baseline Metrics

Google Analytics (GA4):

• Organic traffic (overall and by landing page)
• Conversion rates
• Bounce rates
• Average session duration

Google Search Console:

• Impressions and clicks by page
• Average position by query
• Click-through rates
• Indexing status (how many pages indexed)

Core Web Vitals:

• LCP, INP, CLS for top pages
• Mobile vs desktop performance

Backlink Profile:

• Total backlinks (using Ahrefs, Moz, or Semrush)
• Referring domains
• Top linked pages

Screenshot everything. When traffic drops post-migration, you'll need to prove whether it's migration-related or seasonal/algorithm-related.

Source: SEO Credo migration checklist

Step 5: Create Comprehensive Redirect Map

This is the most important pre-migration task.

Process:

1. Export all URLs from site crawl
2. Map each old URL to new equivalent
3. Note URLs that won't have direct equivalents
4. Prioritise by traffic and backlinks
5. Create redirect implementation file

Example redirect map:

Old URL	New URL	Priority	Traffic	Backlinks	Notes
/services/web-design/	/services/web-development/	High	450/mo	23	Renamed service
/blog/2020/01/post/	/blog/post/	Medium	120/mo	5	Removing date
/old-category/	/services/	Medium	80/mo	2	Category merged
/contact-us/	/contact/	High	300/mo	15	Simplified URL

Handle edge cases:

• Deleted content with backlinks: Redirect to most relevant remaining page
• Merged content: Multiple old URLs can redirect to one new URL
• Split content: One old URL should redirect to primary new equivalent

Test redirects on staging. Visit every old URL and verify it redirects correctly. Don't assume—verify.

Source: Ninja Promo migration checklist

During Migration: Critical Execution Steps

Preserve Technical SEO Elements

Crawlability:

• Verify robots.txt allows search engine access
• Remove any noindex tags accidentally left from staging
• Check for accidental blocks in platform settings

Common mistake: Shopify stores launched with password protection still enabled. Search engines can't access the site. Traffic goes to zero. We see this multiple times per year.

Canonical Tags:

• Preserve or update canonical tags for all pages
• Self-referencing canonicals (page canonicals to itself) are standard
• Cross-domain canonicals only when intentionally consolidating domains

Internal Links:

• Update all internal links to point to new URLs
• Don't rely on redirects for internal navigation (wastes link equity)
• Scan for hardcoded old URLs in content

Structured Data:

• Migrate all Schema.org markup (Product, Article, FAQ, LocalBusiness, Review, etc.)
• Test with Google's Rich Results Test
• Particularly important for AI search visibility

2025 AI search context: ChatGPT, Perplexity, and Google AI Overviews rely on structured data to understand and surface your content. Losing structured data during migration means becoming invisible to AI search—a fast-growing channel showing 527% year-over-year growth.

Source: BrightEdge 2025 migration guide

Metadata Migration

Don't lose custom metadata:

Meta titles and descriptions:

• Every page should have unique, optimised titles and descriptions
• Don't accept platform defaults ("Product Name | Site Name")
• Preserve custom metadata from old site

Heading hierarchy (H1-H6):

• Maintain logical heading structure
• One H1 per page (typically page title)
• H2s for main sections, H3s for subsections

Image alt text:

• Accessibility requirement (WCAG 2.2 AA)
• SEO benefit for image search
• Often lost during platform migrations
• Proper accessibility compliance during migration is critical—UK businesses serving EU customers now face up to €3M penalties for non-compliance after the European Accessibility Act enforcement began in June 2025

Open Graph and Twitter Card tags:

• Controls how content appears when shared on social media
• Different from meta descriptions
• Often forgotten during migrations

Source: Semrush migration checklist

Performance Optimisation

Migration is your opportunity to improve Core Web Vitals, not degrade them.

Largest Contentful Paint (LCP):

• Optimise hero images (next-gen formats, proper sizing, lazy loading)
• Reduce server response time
• Eliminate render-blocking resources

Interaction to Next Paint (INP):

• Minimise JavaScript execution
• Optimise third-party scripts
• Reduce DOM size

Cumulative Layout Shift (CLS):

• Set explicit dimensions for images and embeds
• Avoid inserting content above existing content
• Use transform animations instead of layout-shifting properties

Target benchmarks:

• LCP: Under 2.5 seconds
• INP: Under 200ms
• CLS: Under 0.1

Measure before migration. Measure after migration. If performance degrades, you'll lose rankings even with perfect redirects.

Source: Shopify replatforming strategies

Post-Migration Monitoring & Recovery

The 90 days after launch determine success or failure.

Critical Monitoring Period

Week 1-2: Immediate Checks

Day 1-3:

• Verify all critical redirects are working
• Check for 404 errors in Search Console
• Submit new XML sitemap to Search Console
• Request indexing of key pages
• Monitor server logs for crawl errors

Day 4-14:

• Daily Search Console monitoring for coverage errors
• Traffic trend analysis (expect 10-25% temporary dip)
• Conversion rate monitoring (traffic quality, not just quantity)
• Backlink preservation verification

Week 3-6: Performance Tracking

• Organic traffic trends (by landing page)
• Keyword ranking fluctuations (track top 50-100 keywords)
• Core Web Vitals monitoring (LCP, INP, CLS)
• Conversion rate comparison to pre-migration baseline
• Crawl error resolution

Week 7-12: Stabilisation

• Traffic should be approaching or exceeding pre-migration levels
• Rankings should stabilise
• Conversion rates should normalise
• Address any lingering technical issues

Expected timeline for well-executed migrations:

• 4-8 weeks for complete traffic recovery
• 30-60 days for ranking stabilisation
• 2-3 months for full search engine reprocessing

Source: Springhill Marketing migration timeline, ThreeSphere migration timeline

Google Search Console Monitoring

Coverage Tab:

• Shows errors, warnings, valid pages, and excluded pages
• Fix errors immediately (404s, server errors, redirect chains)
• Monitor for soft 404 warnings (redirects to irrelevant pages)

Performance Tab:

• Track impressions, clicks, average position, CTR
• Filter by page to identify traffic drops on specific URLs
• Compare date ranges (last 28 days vs previous 28 days)

Core Web Vitals Tab:

• Monitor LCP, INP, CLS post-migration
• Identify pages failing Core Web Vitals thresholds
• Prioritise fixes for high-traffic pages

Index Coverage:

• Verify new pages are being indexed
• Check for unexpected exclusions
• Submit new sitemap if not automatically discovered

Common post-migration Search Console errors:

• 404 errors: Missing redirects
• Soft 404s: Redirects to irrelevant content
• Server errors (5xx): Platform configuration issues
• Redirect chains: Multiple redirects instead of direct mapping
• Noindex tags: Accidentally blocking search engines

Fix these immediately. Every day you leave them unresolved is a day you're losing traffic and rankings.

Source: AdLift migration monitoring

Key Benchmarks to Monitor

Traffic metrics:

• Overall organic sessions (should recover to baseline within 4-8 weeks)
• Landing page performance (individual page traffic trends)
• Traffic by channel (ensure organic traffic recovers, not just total traffic)

Technical metrics:

• Page load speed and Core Web Vitals (should match or exceed pre-migration)
• Page indexing rates (new pages should be indexed within 4-6 weeks)
• Crawl errors (should decrease to near zero within 2-4 weeks)

Ranking metrics:

• Keyword rankings for priority terms (may fluctuate for 4-8 weeks, then stabilise)
• SERP feature appearances (featured snippets, People Also Ask, etc.)
• Rich result eligibility (verify structured data is working)

Conversion metrics:

• Conversion rate (traffic quality matters more than quantity)
• Bounce rate changes (increased bounce rate indicates UX issues)
• Time on page and engagement metrics

Don't just monitor traffic—monitor revenue. A migration that maintains traffic but destroys conversion rate has failed.

Source: Creole Studios migration checklist

Structured Data & AI Search Preservation (2025 Focus)

In 2025, structured data isn't just for traditional SEO—it's critical for AI search visibility.

Why This Matters for Migrations

AI search traffic grew 527% year-over-year. ChatGPT, Perplexity, and Google AI Overviews rely heavily on structured data to understand and surface content.

If you lose structured data during migration, you become invisible to AI search engines.

Schema Types to Preserve

Product (e-commerce):

{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Product Name",
  "description": "Product description",
  "image": "product-image.jpg",
  "offers": {
    "@type": "Offer",
    "price": "99.00",
    "priceCurrency": "GBP",
    "availability": "https://schema.org/InStock"
  },
  "aggregateRating": {
    "@type": "AggregateRating",
    "ratingValue": "4.8",
    "reviewCount": "127"
  }
}

Article (blog content):

{
  "@context": "https://schema.org",
  "@type": "Article",
  "headline": "Article Title",
  "author": {
    "@type": "Person",
    "name": "Author Name"
  },
  "datePublished": "2025-11-05",
  "image": "article-image.jpg"
}

FAQ (common questions):

{
  "@context": "https://schema.org",
  "@type": "FAQPage",
  "mainEntity": [{
    "@type": "Question",
    "name": "Question text?",
    "acceptedAnswer": {
      "@type": "Answer",
      "text": "Answer text."
    }
  }]
}

LocalBusiness (service businesses):

{
  "@context": "https://schema.org",
  "@type": "LocalBusiness",
  "name": "Business Name",
  "address": {
    "@type": "PostalAddress",
    "streetAddress": "123 Street",
    "addressLocality": "London",
    "postalCode": "SW1A 1AA"
  },
  "telephone": "+44-20-1234-5678",
  "openingHours": "Mo-Fr 09:00-17:00"
}

Source: BrightEdge 2025 migration guide

Pre-Migration Structured Data Audit

Document current implementation:

1. Crawl site with Screaming Frog (extracts structured data)
2. Export all schema types currently implemented
3. Identify which pages have which schema
4. Test with Google Rich Results Test
5. Note any errors or warnings

Plan migration strategy:

• WordPress plugins often handle schema automatically (Yoast, Rank Math, Schema Pro)
• Shopify requires manual implementation in theme files
• Custom platforms need JSON-LD embedded in templates

Post-migration verification:

1. Re-crawl new site
2. Compare schema coverage to pre-migration
3. Test with Rich Results Test
4. Fix any missing or broken structured data
5. Monitor Search Console for rich result errors

Without this process, you'll lose structured data during migration—and lose AI search visibility along with it.

Common Migration Mistakes (and How to Avoid Them)

1. Launching Without Testing Redirects

The mistake: Assuming redirects work because they're "in the system." Not actually testing them.

The fix:

• Test every high-priority redirect manually
• Use redirect checking tools (Screaming Frog, Redirect Mapper)
• Verify on staging before launch
• Re-verify on production immediately after launch

Real scenario we encountered: Client migrated 2,400 product pages from WordPress to Shopify. Redirects were "implemented" according to the developer. Post-launch, we discovered 70% of redirects returned 404s due to a Shopify app misconfiguration.

Traffic dropped 63% overnight. Took 11 days to fix all redirects. Took 4 months to fully recover traffic.

2. Forgetting About Images and PDFs

The mistake: Redirecting HTML pages but forgetting about linked resources—images, PDFs, downloadable resources, videos.

The fix:

• Crawl for all resource types, not just HTML pages
• Redirect or migrate all images referenced in backlinks
• Redirect all PDFs that receive direct traffic
• Update download links in content

Why this matters: That whitepaper PDF you published two years ago might have 40 backlinks and rank #3 for a valuable keyword. If you delete it without redirecting, you lose all that value.

3. Changing Too Much at Once

The mistake: Migrating platform AND redesigning completely AND changing URL structure AND rebranding simultaneously.

The fix: Isolate variables. If you must change platforms, keep URLs the same where possible. If you must redesign, keep the platform the same initially.

HireRoad case study revisited: They merged three domains AND rebranded simultaneously. High-risk move. It only succeeded because they tested almost 1,000 redirects before launch and had comprehensive monitoring.

Most businesses don't have that level of rigour. Don't stack risks unnecessarily.

4. No Post-Launch Monitoring Plan

The mistake: Launching and assuming everything is fine because no immediate disaster occurs.

The fix:

• Daily Search Console monitoring for first 14 days
• Weekly traffic analysis for first 90 days
• Dedicated person responsible for monitoring and fixes
• Clear escalation process when issues appear

Real scenario: Client launched Friday afternoon. Developer went on holiday Monday. Small redirect issue snowballed over the weekend. By Monday, 400+ pages were returning 404s.

No one was monitoring. No one noticed until the following Wednesday when the client checked Google Analytics and saw 52% traffic drop.

Launches should happen early in the week with full team availability for at least 48 hours post-launch.

5. Treating Migration as IT Project, Not Marketing Project

The mistake: IT department handles migration without SEO involvement until it's too late.

The fix:

• SEO specialist involved from initial planning
• Marketing team defines success criteria
• Technical SEO audit before any development
• SEO review of staging before launch approval

The £3.8M loss happened because IT consultants rejected SEO recommendations as "too complex." Don't let technology decisions override marketing fundamentals.

Your Migration Implementation Roadmap

Phase 1: Pre-Migration Planning (Weeks 1-4)

Week 1-2:

• Full site backup (database + files)
• Crawl current site with Screaming Frog
• Document baseline metrics (GA4, Search Console, Core Web Vitals)
• Export all content and metadata
• Identify all URLs requiring redirects

Week 3-4:

• Create comprehensive redirect map (old URL → new URL)
• Set up staging environment
• Plan structured data migration
• Define success metrics and monitoring plan
• Assign responsibilities (who monitors what)

Success criteria: Complete documentation of current state, clear redirect strategy, tested staging environment.

Phase 2: Execution Phase (Weeks 5-8)

Week 5-6:

• Build new site on staging
• Implement 301 redirects (test on staging)
• Migrate all content with metadata preservation
• Implement structured data (Schema.org)
• Configure technical SEO elements (robots.txt, sitemap, canonicals)

Week 7-8:

• Performance optimisation (Core Web Vitals)
• Test all redirects manually
• Verify structured data with Rich Results Test
• Mobile testing (actual devices, not just responsive preview)
• Final QA checklist before launch approval

Success criteria: Staging site matches or exceeds current site performance, all redirects tested and working, structured data verified.

Phase 3: Launch & Immediate Monitoring (Week 9-10)

Day 1-3:

• Launch new site (early in week, full team available)
• Submit new sitemap to Search Console
• Verify all critical redirects working on production
• Check for 404 errors in Search Console
• Monitor server logs for issues

Day 4-14:

• Daily Search Console monitoring
• Traffic analysis (expect 10-25% temporary dip)
• Fix any emerging redirect issues immediately
• Monitor conversion rates (not just traffic)
• Core Web Vitals monitoring

Success criteria: No critical errors, redirects working, temporary traffic dip within expected range.

Phase 4: Recovery & Optimisation (Weeks 11-24+)

Week 11-14:

• Traffic trend analysis (should be recovering)
• Keyword ranking monitoring
• Address any lingering technical issues
• Optimise underperforming pages
• Continue Search Console monitoring

Week 15-24:

• Full traffic recovery expected (4-8 weeks post-launch)
• Ranking stabilisation
• Performance optimisation based on real user data
• Identify and fix any remaining redirect issues
• Document lessons learned

Success criteria: Traffic matches or exceeds pre-migration baseline, rankings stable or improved, conversion rates normalised.

What This Looks Like in Practice

At Numen Technology, we treat migrations as high-stakes projects requiring partnership through all phases—pre-launch, launch, and 90-day recovery.

Our migration approach:

1. Pre-migration audit: Comprehensive baseline documentation and redirect mapping
2. Structured data preservation: Schema.org migration for traditional SEO and AI search visibility
3. Performance engineering: Core Web Vitals optimisation during migration
4. 90-day post-launch monitoring: Weekly check-ins, immediate issue resolution, data-driven optimisation
5. Continuous measurement: Traffic, rankings, conversions tracked against baseline

We don't build beautiful websites that lose your organic traffic. We build websites that protect and grow the traffic you've spent years building.

Launch is just the beginning for migration projects. The real work happens in the 90 days after, when traffic either recovers and grows or drops and never comes back.

Most agencies disappear after launch. We don't.

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Planning a website migration? Contact us for a migration SEO audit. We'll analyse your current site, identify risks specific to your migration, and provide a detailed redirect map and migration plan. No generic checklist—specific strategy for your situation.