The State of CMS Migration Readiness 2026 (dataset)

Eleven SEO and security readiness signals (HTTPS, title quality, meta description, viewport, canonical, structured data, Open Graph, single H1, HSTS, CSP, X-Content-Type-Options) measured across a random sample of the Tranco top 80,000 websites — 48,588 domains drawn, 27,385 reachable and measurable — with per-platform aggregates for every CMS with ≥30 measurable sites. Headline finding: WordPress and Drupal score identically on overall readiness but fail in opposite directions (structured data vs security headers). Method in brief: one polite, identified HTTP GET per homepage; no crawling. Signals are objective presence checks observable from a single fetch. CMS inferred from response fingerprints (conservative; unfingerprinted sites grouped as Unknown). Unreachable/bot-walled sites excluded rather than counted as failures. Licensed CC BY 4.0 — reuse with attribution and a link to the study page. Full study, method & limitations, and living data table: replatformradar.com/research/cms-migration-readiness-2026