{"id":676,"slug":"wordpress-cwv-causal-attribution-2026","title":"WordPress CWV gap causal decomposition (May 2026): ~40-50% hosting/TTFB, ~20-30% page builders, ~15-20% plugins, ~5-10% core, ~5-10% theme","kind":"reference","scope":"business","status":"current","audiences":["kevin","claude-code","candid-team"],"topics":["core-web-vitals","wordpress","page-builders","hosting-platforms"],"reference_body":"**Best decomposition the public data supports:**\n\n| Factor | Share of gap | Evidence | Confidence |\n|---|---|---|---|\n| **Hosting / TTFB** | ~40-50% | Only 32% of WP origins have good TTFB (CoreDash citing CrUX, Jun 2025). Moving shared→managed routinely flips LCP from poor to good with no other change. | High |\n| **Page builder bloat (Elementor/Divi/WPBakery)** | ~20-30% | 2025 Web Almanac: builder optimizations \"do not completely erase the performance gap.\" Elementor→Gutenberg migrations consistently show 1.5-2.5s LCP reductions. | Directional |\n| **Plugin sprawl / third-party scripts** | ~15-20% | 2024 Web Almanac Performance chapter identifies third-party scripts (behaviour tracking, consent providers, CDNs) as primary cause of long Presentation Delay (poor INP). | Directional |\n| **WordPress core / Gutenberg** | ~5-10% | Median Lighthouse mobile perf 33 (2023) → 38 (2024) → 41 (2025). Core lazy-loading, fetchpriority=\"high\" on LCP image, persistent block-style cache, AVIF pipeline. | High |\n| **Theme choice** | ~5-10% | Lightweight themes (Kadence, GeneratePress, Hello) score 90+ PSI; bloated multipurpose themes routinely fail. | Directional |\n\n**Implications for decision-making:**\n\n- **Biggest single lever is hosting.** A WP + Gutenberg + Kadence/GeneratePress site on Kinsta/WP Engine/Cloudways can plausibly match an Astro-on-Cloudflare site in the field. See [[wp-gutenberg-managed-host-matches-astro]].\n- **A WP + Elementor/Divi/WPBakery site on shared hosting effectively cannot pass CWV without aggressive remediation.** Median pre-optimization LCP 3.8-5.2s is structurally above the 2.5s threshold.\n- **A custom Astro/SvelteKit site on Vercel/Cloudflare Pages will pass CWV by default** because edge TTFB is 20-50ms and Astro's islands architecture ships near-zero JS for non-interactive content.\n\n**The \"WordPress is slow\" mental model is wrong at the platform level and right at the typical-configuration level.** The CMS is not the bottleneck; the median configuration of the CMS is.","rationale_body":null,"metadata":null,"links":{"outgoing":[{"slug":"elementor-lcp-3-8-to-5-2-seconds","title":"Elementor sites show pre-optimization median mobile LCP of 3.8–5.2s — well above Google's 2.5s threshold","kind":"reference","scope":"business","link_type":"depends-on"},{"slug":"wordpress-median-js-528kb-counterintuitive","title":"WordPress median mobile JS payload is 528 KB — smaller than Wix (1,462 KB) and Squarespace (1,314 KB), yet WordPress performs worse in the field","kind":"reference","scope":"business","link_type":"depends-on"},{"slug":"page-builder-market-share-2025-elementor-43pct","title":"WordPress page-builder market share, 2025 Web Almanac: Elementor 43% (down from 56% in 2024); Gutenberg 18% (up from ~12%); WPBakery 13%; Divi 10%","kind":"reference","scope":"business","link_type":"depends-on"},{"slug":"wp-gutenberg-managed-host-matches-astro","title":"A well-optimized WordPress + Gutenberg + Kadence/GeneratePress site on managed hosting can plausibly match an Astro-on-Cloudflare site in CWV","kind":"reference","scope":"business","link_type":"relates-to"},{"slug":"managed-wp-ttfb-hostingstep-2025","title":"Managed WordPress host TTFB benchmarks (HostingStep 2025, 34 hosts, 1,960+ days of 24/7 monitoring)","kind":"reference","scope":"business","link_type":"depends-on"}],"incoming":[{"slug":"research-brief-wp-builders-vs-modern-stacks-2026","title":"Research brief: WordPress + Page Builders vs Modern Custom Stacks — sourced performance comparison (piece 18)","kind":"reference","scope":"business","link_type":"depends-on"}]},"created_at":"2026-05-22T21:24:18.386Z","updated_at":"2026-05-22T21:24:18.386Z"}