Detailed checklist for crawling historical URLs, implementing permanent 301 redirects, preserving semantic H1/H2 hierarchies, and validating structured data ahead of DNS cutover.
1. Why Website Migrations Often Lose Traffic
When companies redesign their website, creative agencies often discard legacy URLs or redirect hundreds of old blog posts blindly to the homepage. To Google, this is treated as a soft-404 error, wiping out years of accumulated search authority.
Every URL that currently receives organic clicks must either remain unchanged or point via an explicit HTTP 301/308 redirect to its exact modern equivalent.
2. Preserving On-Page Content Semantics
Search engines rank pages based on the specific questions they answer. If a legacy page ranked for technical terms, replacing detailed technical copy with vague marketing slogans will cause keyword decay.
Ensure the new React Server Components preserve the primary semantic headings (H1, H2), structured bullet points, and Schema.org markup.
3. Cutover Monitoring & GSC Inspection
Immediately upon DNS propagation, verify that server response headers return HTTP 200 on new routes and HTTP 301/308 on legacy routes.
Monitor Google Search Console Index Coverage daily for the first 14 days to identify any crawl anomalies before they impact organic business enquiries.
Checklist
- 01Export complete Google Search Console URL impressions and Screaming Frog crawl data
- 02Create 1:1 permanent 301 redirect map in next.config.mjs (avoid wildcard homepage redirects)
- 03Preserve existing page H1 tags, meta titles, and canonical URL structure
- 04Test responsive layout shifts (CLS < 0.1) and Largest Contentful Paint (LCP < 2.0s)
- 05Inspect Googlebot rendering on staging and submit fresh sitemap.xml on DNS switch