Website Migration Guide

A successful website migration starts months before any code changes. The planning phase is where you establish your goals, assess risks, and build the project timeline that keeps everything on track. According to a study by Ahrefs, 34% of websites that migrate without a documented plan experience significant organic traffic losses lasting more than six months.

Begin by clearly defining why you're migrating. Common reasons include replatforming (e.g., moving from WordPress to a headless CMS), domain consolidation, HTTPS implementation, site redesign, or infrastructure upgrades. Each migration type carries different risk profiles and requires different preparation.

Document your current site's baseline metrics before making any changes. This includes organic traffic by page, keyword rankings for your top 50-100 terms, backlink profile, Core Web Vitals scores, conversion rates, and revenue attribution. These benchmarks become your success criteria post-migration.

Assemble your migration team early. You'll need a project manager, developers, an SEO specialist, a QA tester, and stakeholders from content and marketing. Establish a communication cadence, typically weekly standups during planning and daily during execution. Create a shared migration document that tracks every URL, every redirect, and every content change. The more thorough your planning phase, the smoother your execution will be.

Your pre-migration checklist is the safety net that catches issues before they become costly problems. This phase typically takes two to four weeks, depending on site complexity, and involves a thorough audit of everything that could break during the transition.

Start with a complete crawl of your existing site using tools like Screaming Frog or Sitebulb. Document every URL, its status code, canonical tag, meta data, and internal linking structure. Export your XML sitemap and cross-reference it against your crawl data to identify any orphaned pages or content gaps. Back up your entire database, media files, and server configuration. Store backups in at least two separate locations.

Audit your current analytics and tracking implementations. Document every Google Tag Manager container, custom event, conversion goal, and third-party integration. These are frequently lost during migrations and can take weeks to notice if not properly tracked. Review your robots.txt file and any server-level redirects currently in place.

Prepare your staging environment to mirror production as closely as possible. Test the migration on staging first, running the same crawl tools and comparing results against your baseline. Verify that all forms, interactive elements, e-commerce functionality, and third-party integrations work correctly. Create a rollback plan in case the migration fails, including exact steps to revert to the previous version within two hours.

Redirect mapping is the single most critical SEO task in any website migration. Google has repeatedly confirmed that even properly implemented redirects can result in a temporary ranking fluctuation, but missing or broken redirects almost always cause permanent traffic losses. Every URL on your old site needs a corresponding destination on the new site.

Build a comprehensive redirect map in a spreadsheet with columns for the old URL, new URL, redirect type (301 vs 302), priority level, and monthly organic traffic. Prioritize pages by traffic and revenue impact. Your top 20% of pages likely drive 80% of your organic value, so these redirects must be perfect.

Use 301 (permanent) redirects for any URL that has changed. Avoid redirect chains where URL A points to URL B which points to URL C. Each redirect should go directly to the final destination. Google will follow up to 10 redirects in a chain, but each hop dilutes crawl efficiency and can slow page delivery.

Pay special attention to URL pattern changes. If your blog moved from /blog/post-name to /articles/post-name, you can use regex-based redirect rules to handle these programmatically rather than creating individual rules for hundreds of pages. Test every redirect on staging. Tools like Screaming Frog can crawl your old URL list against the staging environment to verify each redirect resolves correctly. Flag any 404s immediately and add them to your redirect map before going live.

Migration day should be anti-climactic if your planning and testing were thorough. Choose a low-traffic window for the cutover, typically a Tuesday or Wednesday morning when traffic is predictable and your full team is available. Avoid launching during holidays, major marketing campaigns, or peak sales periods.

Follow your migration runbook step by step. Deploy the new site, implement all redirects, update your XML sitemap to reflect new URLs, and submit the updated sitemap in Google Search Console. If you're changing domains, use the Change of Address tool in Search Console to signal the move to Google. Update your robots.txt file to ensure crawlers can access all new URLs.

Run an immediate crawl of the new site to catch any broken links, missing redirects, or unexpected 404 errors. Verify that your canonical tags point to the correct new URLs, not the old ones. Check that hreflang tags, structured data, and Open Graph meta data have all been updated. Confirm that analytics tracking fires correctly on every page.

Monitor your server logs in real time during the first 24 hours. Watch for spikes in 404 errors, unusual crawl patterns from Googlebot, or any server performance issues under the new configuration. Have your team available for rapid fixes. Document every issue encountered and its resolution for future reference. Communicate the migration status to stakeholders with regular updates throughout the day.

The weeks following a migration are when problems surface. Google typically re-crawls and re-indexes a migrated site over two to twelve weeks, depending on site size and crawl budget. During this period, ranking fluctuations are normal, but sustained drops indicate issues that need immediate attention.

Set up a monitoring dashboard that tracks key metrics daily for the first 30 days, then weekly for the next 90 days. Monitor organic traffic, crawl stats in Google Search Console, index coverage reports, keyword rankings for your priority terms, and conversion rates. Compare these against your pre-migration baselines to identify anomalies.

Watch Google Search Console's Index Coverage report closely. Look for spikes in "Excluded" pages, "Crawled but not indexed" URLs, or new crawl errors. These often indicate redirect issues or content quality signals that need attention. Check the Page Experience report to ensure Core Web Vitals haven't degraded on the new platform.

Keep your old redirects in place for at least one year, ideally permanently. Removing redirects prematurely causes link equity loss and creates broken backlinks. Run monthly crawls for the first six months to catch any redirect decay or new 404 errors. After 90 days, conduct a comprehensive post-migration audit comparing all KPIs against your baseline. Document lessons learned and share them with your team to improve future migration projects.