Every year, well-designed new websites launch and quietly lose a chunk of the search traffic the old site had earned. The new platform usually is not the problem. The problem is the hundreds of small details that nobody mapped: URLs that changed, redirects that were never set, forms that stopped reaching the CRM, a tracking tag that disappeared.
Migrations are not risky because they are complex. They are risky because they are detailed. A checklist is the cure.
Phase 1: Inventory everything
Before any design or build work, capture what exists:
- Every URL, from a crawl, your XML sitemap and analytics. Include PDFs, landing pages and old campaign pages that still get traffic or links.
- Top pages by organic traffic, conversions and backlinks.
- Forms and integrations: CRM, marketing automation, chat, payment, booking.
- Tracking: analytics, tag manager, ad pixels, consent tools.
- Technical settings: robots.txt, canonical tags, hreflang, structured data.
This inventory is the baseline you will test against.
Phase 2: Map and plan
Redirect map
Map every old URL to the most relevant new URL, not to the home page. Google’s documentation on site moves recommends mapping old URLs to their new equivalents with permanent server-side redirects (Google Search Central).
Content decisions
Decide what is kept, merged, rewritten or retired. If you retire a page with valuable traffic or links, redirect it to the closest relevant page.
Performance baseline
Record Core Web Vitals and load times on key templates now, so you can prove the new site is faster. Across the web, only 48% of mobile sites pass all three Core Web Vitals (HTTP Archive); a migration is the perfect chance to be in the better half.
Phase 3: Build and test in staging
- Build on a staging environment that search engines cannot index.
- Recreate or improve metadata, headings and structured data for key pages.
- Test every redirect in the map, automatically if possible.
- Submit every form and confirm the data arrives where it should.
- Check analytics and consent tools fire correctly.
- Run accessibility and performance checks on key templates.
Phase 4: Launch with zero downtime
- Choose a quiet window, based on your traffic data.
- Lower DNS TTLs in advance if the domain or hosting changes, so the switch propagates quickly.
- Freeze content on the old site shortly before launch.
- Deploy, then verify immediately: home page, key templates, redirects, forms, tracking and HTTPS.
- Allow search engines to index the new site and submit the updated sitemap.
- Keep a rollback plan ready: the old site and its backups available until you are confident.
Phase 5: Monitor closely
For the first few weeks:
- check crawl errors and 404s daily at first, fixing missing redirects quickly;
- compare rankings and traffic for your top pages against the baseline;
- watch form submissions and conversion rates;
- review Core Web Vitals once enough real-user data is available.
Where AI helps
Migrations involve a lot of repetitive, structured work that AI handles well:
- matching old URLs to new ones by content similarity, for a person to confirm;
- auditing hundreds of pages for missing titles, descriptions and headings;
- summarising crawl reports into prioritised fixes;
- rewriting or consolidating outdated content, reviewed by an editor.
The decisions, especially which content to keep and where each URL should go, still need people who understand the business.
The takeaway
A migration is a chance to make your site faster, cleaner and easier to manage. Treat it as a detailed project with an inventory, a map, testing, a careful launch and close monitoring, and you can switch platforms without your visitors or search engines noticing anything except the improvement.
Migrations and ongoing website care are part of our website development service. Before launch, run through our AI-assisted QA checklist.
