How do I handle redirects during site migrations?

Managing Redirects During Website Migrations

Site migrations represent some of the most challenging situations in web management. Moving to new infrastructure, changing domain names, restructuring URL hierarchies, or switching content management systems all require careful redirect planning. Improperly executed migrations can devastate SEO visibility, confuse users, and damage the user experience accumulated over years. Conversely, well-planned redirects during migrations preserve ranking authority, maintain user experience, and ensure search engines successfully crawl and index the new structure.

A strategic approach to migration redirects requires understanding your current URL landscape, planning the destination structure meticulously, implementing redirects systematically, and monitoring the transition carefully. The goal is making the migration essentially invisible to users and search engines—they should seamlessly follow redirects to the new location without realizing anything changed.

Pre-Migration Planning and Audit

Audit Your Current URL Structure

Before implementing any redirects, thoroughly understand your existing site:

Inventory Current Pages:

• Use Screaming Frog or Google Search Console to identify all indexed pages
• Note current URL structure and patterns
• Identify parameter usage (tracking parameters, session IDs, etc.)
• Document any special redirects already in place

Identify High-Value Pages:

• Pages with most organic traffic
• Pages with most backlinks
• Pages ranking for important keywords
• Pages with high conversion rates

These are where migration mistakes hurt most. They deserve extra care.

Find Duplicate Content:

• Identify multiple URLs with identical content
• Plan consolidation (which URL should be canonical?)
• Remove unnecessary versions post-migration

Categorize URLs by Type:

• Homepage
• Service/Product pages
• Blog posts
• Category/Archive pages
• Special pages (about, contact, etc.)
• Old or outdated pages (candidates for removal)

Document Your Redirect Mapping

Create a comprehensive mapping document showing where each URL will go:

Spreadsheet Template:

Old URL	New URL	Redirect Type	Priority	Notes
/old-product	/new-product	301	High	Top traffic page
/article-2020	/blog/updated-article	301	Medium	Outdated article
/store	/shop	301	High	Main category

This document becomes your implementation blueprint and post-migration reference.

Choosing Redirect Strategy

Strategy 1: One-to-One URL Mapping

Approach: Each old URL redirects to a specific new URL

/old-page → /new-page
/old-product → /new-product
/old-service → /new-service

Best For:

• Similar URL structures in old and new
• Straightforward migrations (same CMS, same domain)
• Preserving individual page rankings
• Content that's been updated rather than reorganized

Pros:

• Preserves all link authority to specific pages
• Maintains granular tracking of page-level migration
• Users land on exact content they sought

Cons:

• Requires creating many redirect rules
• Time-consuming mapping and implementation
• Difficult to manage if URL structure changes significantly
• Might create hundreds or thousands of redirects

Strategy 2: Category-Level Consolidation

Approach: Group old URLs into broader categories

/product/old-item-1 → /products
/product/old-item-2 → /products
/product/old-item-3 → /products

Best For:

• Consolidating outdated products/services
• Significant restructuring
• Removing pages that shouldn't exist post-migration

Pros:

• Fewer redirect rules to maintain
• Cleaner new structure
• Useful when consolidating duplicate content

Cons:

• Users might not find exact product/page
• Loses some link authority (redirect to category vs. specific page)
• Less precise tracking

Strategy 3: Hybrid Approach

Approach: One-to-one for important pages, category-level for others

/services/consulting → /consulting-services (high-traffic, one-to-one)
/services/old-product-1 → /services (low-traffic, category redirect)
/services/old-product-2 → /services (low-traffic, category redirect)

Best For: Most real-world migrations

Pros:

• Balances preservation and simplicity
• Protects high-value pages while simplifying low-value redirects
• Flexible approach

Implementation Timing and Phases

Phase 1: Pre-Migration (4-6 weeks before)

Immediate Actions:

1. Finalize URL mapping document
2. Create new site structure
3. Develop all content for new site
4. Set up new hosting/infrastructure if needed
5. Test thoroughly before migrating live

Migration Announcement:

• Internal team communication
• Document the timeline
• Identify responsible parties for each component

Phase 2: Migration Cutover (1-2 days)

The Big Day:

1. Implement all 301 redirects on old site
2. Deploy new site on new URL structure
3. Point DNS to new location (if changing domains)
4. Monitor for issues throughout the day
5. Have rollback plan ready if critical issues occur

Timing Considerations:

• Perform migration during off-peak hours
• Avoid launching before weekends (limited support)
• Avoid launching before major holidays
• Schedule maintenance windows if possible

What NOT to Do:

• Don't launch new site before redirects are tested
• Don't assume redirects work without verification
• Don't launch during peak traffic hours
• Don't migrate without having a rollback plan

Phase 3: Post-Migration Monitoring (Weeks 1-8)

Week 1: Critical Monitoring:

• Monitor server error logs for 404 errors
• Check Google Search Console for crawl errors
• Verify all high-priority pages are accessible
• Monitor traffic for unexpected drops
• Check user feedback for issues

Weeks 2-4: Transition Period:

• Submit updated sitemap to Google Search Console
• Monitor rankings for key pages
• Check that Google is crawling new URLs
• Verify redirects processing correctly
• Address any issues found

Weeks 4-8: Complete Recovery:

• Monitor for full index migration
• Check rankings stabilization
• Plan removal of temporary redirects
• Document lessons learned

Implementing Redirects Correctly

Server-Level Implementation

Apache (.htaccess):

RewriteEngine On
RewriteCond %{HTTP_HOST} ^old-domain\.com$ [OR]
RewriteCond %{HTTP_HOST} ^www\.old-domain\.com$
RewriteRule ^(.*)$ https://new-domain.com/$1 [R=301,L]

# Specific URL redirects
Redirect 301 /old-page https://new-domain.com/new-page
Redirect 301 /old-product https://new-domain.com/new-product

Nginx:

server {
    listen 80;
    server_name old-domain.com www.old-domain.com;
    return 301 https://new-domain.com$request_uri;
}

location /old-page {
    return 301 https://new-domain.com/new-page;
}

Using PHP for Dynamic Redirects

If migration involves changing URL parameters or structure:

<?php
// Redirect old URL structure to new
if (isset($_GET['id'])) {
    $id = $_GET['id'];
    // Look up where this ID maps in new structure
    $new_url = lookup_new_url($id);
    header('HTTP/1.1 301 Moved Permanently');
    header('Location: ' . $new_url);
    exit;
}
?>

Using CDN Redirects

If using Cloudflare or similar CDN:

Cloudflare Rules:

URL: domain.com/old-page
Redirect to: https://domain.com/new-page
Status code: 301

Cloudflare allows bulk import of redirects via CSV for large migrations.

Handling Special Migration Scenarios

Scenario: Domain Migration

Old: example.com → New: newexample.com

Implementation:

HTTP or Server: Redirect all HTTP requests to HTTPS
Domain Redirect: Redirect all requests from old domain to new domain
Example: 301 https://example.com/* → https://newexample.com/*

Considerations:

• Keep old domain active and redirecting for at least 1-2 years
• Update DNS records carefully (both sites might be in DNS temporarily)
• Ensure SSL certificates valid for both domains during transition

Scenario: URL Structure Reorganization

Old: /category/item → New: /items/category/item

Implementation:

• Map individual old URLs to new structure
• Can use regex rewrite rules if structure is predictable:

RewriteRule ^category/([a-z-]+)$ /items/category/$1 [R=301,L]

Scenario: CMS Migration

Old: Static site → New: WordPress/Drupal/etc.

Considerations:

• CMS may have its own URL structure requirements
• Consider 301-redirecting old URLs to CMS-friendly structure
• Some CMSs have built-in redirect management tools

Scenario: HTTPS Migration

Old: HTTP site → New: HTTPS site

Implementation:

RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

Considerations:

• Install valid SSL certificate before migration
• Redirect both old domain AND HTTP/HTTPS variations

Monitoring the Migration

Google Search Console

Critical Checks:

1. Ensure new domain/property created in GSC
2. Upload new sitemap
3. Monitor "Crawl Errors" for unexpected issues
4. Watch "Coverage" to ensure pages indexed
5. Check "URL Inspection" for specific pages
6. Monitor "Core Web Vitals" for performance impact

Expected Timeline:

• Immediate: First crawls of new URLs
• 1-2 weeks: Most pages re-indexed
• 2-6 weeks: Rankings stabilize
• 6+ weeks: Complete transition

Server Log Analysis

What to Monitor:

• 404 errors (broken redirects, missing pages)
• 301 response codes (verify redirects working)
• 500 errors (server issues)
• Request volume changes (unexpected drops)
• Referrer patterns (tracking user behavior)

Tools:

• Analyze raw logs with command-line (grep, awk)
• Use log analysis services (Splunk, ELK)
• Platform analytics (Google Analytics, Hotjar)

Traffic Monitoring

Expected Patterns:

• Initial dip (common during migration)
• Recovery over 2-6 weeks
• Return to pre-migration levels by month 2-3
• New domain traffic gradually building

Warning Signs:

• Traffic doesn't recover after 4 weeks
• Specific pages losing traffic significantly
• Bouncing between old and new domains
• 404 errors increasing instead of decreasing

Post-Migration Cleanup

When to Remove Redirects

Timeline:

• Keep 301 redirects minimum 1 year (ideally 2-3 years)
• Never remove redirects in first 6 months
• At 1-2 years, assess if redirect traffic still exists
• Remove redirects to broken links (404s), but keep to valid pages

How to Remove:

• Gradually transition (monitor traffic first)
• Use 404 response instead of redirect if page truly gone
• Or simply remove redirect rules and let browser handle 404

Updating Internal Links

Post-Migration:

• Search for all old URLs in content
• Update internal links to point to new URLs
• Reduces redirect chains (improves performance)
• Can improve crawl efficiency

Tools:

• Find & Replace in CMS
• Custom scripts searching and updating
• Automated tools for link fixing

Monitoring Ongoing

Ongoing Checks:

• Monitor error logs monthly
• Check GSC quarterly
• Update redirect rules as needed
• Plan redirect removal timeline

Common Migration Mistakes

1. Not Testing Redirects Before Deployment

• Always test redirect chains before going live
• Use redirect checker tools
• Verify from multiple locations

2. Wrong Redirect Type (302 Instead of 301)

• Use 301 for permanent moves
• Temporary 302s lose ranking authority
• Update to 301 if extending past "temporary" period

3. Redirect Chains

• URL1 → URL2 → URL3 (bad)
• Update to URL1 → URL3 directly (good)
• Reduces crawl budget waste and improves performance

4. Not Keeping Old Domain Active

• Removing old domain too quickly
• Keep redirecting for 1-2 years minimum
• Some users still have bookmarks/references

5. Insufficient Monitoring

• Don't assume migration went smoothly
• Monitor actively in first weeks
• Address issues promptly before they compound

Conclusion

Successful site migrations require careful planning of your redirect strategy, meticulous implementation of redirect rules, and diligent post-migration monitoring. By conducting thorough URL audits, creating detailed mapping documents, choosing appropriate redirect strategies for your situation, and monitoring the transition carefully, you can migrate websites while preserving SEO visibility, maintaining user experience, and ensuring search engines successfully crawl and index the new structure. The effort invested in proper redirect planning and implementation pays dividends in smooth migrations with minimal traffic loss and ranking fluctuation.