Cacheable resource share and the Core Web Vitals
33.6% of audited sites (69,271) mark 80% or more of their subresources as cacheable and reach 84% good LCP (1.5s median), compared to 78% good LCP (1.6s median) on the 31.0% caching under 20% of resources.
33.6% of sites use 80%+ cacheable resources cacheable resource share, and 84% of those sites have a good LCP, against 82% of all sites.
LCP pass rate
Sites with 80%+ cacheable resources cacheable resource share have a good LCP most often: 84%, against 82% of all sites. Sites with under 20% cacheable resources cacheable share have it least often, at 78%.
Cacheable resource share usage
80%+ cacheable resources is the most used: 33.6% of sites.
LCP phase breakdown by share of cacheable subresources
Across the four LCP sub-parts in Chrome's field data, the largest gap between 80%+ cacheable resources and under 20% cacheable resources sits in time to first byte (TTFB): 620 ms median for 80%+ cacheable resources against 765 ms for under 20% cacheable resources. Overall median field LCP is 1.5s for 80%+ cacheable resources (TTFB 620 ms, load delay 335 ms, load duration 158 ms, render delay 240 ms) versus 1.6s for under 20% cacheable resources.
Understanding cacheable resource share
How subresource Cache-Control coverage speeds up repeat visits and CDN edge hits
Cacheable resource share tracks the percentage of page requests carrying valid Cache-Control or Expires headers. Across 69,271 sites (33.6%) with 80%+ cacheable resources and 49,403 sites (24.0%) at 50% to 79%, 84% and 84% pass field LCP (1.5s and 1.5s median). When cacheability falls to 20% to 49% (11.5%), good LCP drops to 80% (1.6s median), and below 20% cacheable (31.0%, 63,848 sites) good LCP drops to 78% (1.6s median).
Ensure at least 80% of subresources return explicit Cache-Control max-age headers so browsers and CDN edges serve static assets without origin round-trips. Across all audited sites, 33.6% cache 80%+ of resources (84% good LCP) versus 31.0% caching under 20% (78% good LCP).
How cacheable resource share plays out per platform
What the field data shows when you isolate a single CMS or framework.
WordPress 65,509 sites 35.9% of WordPress sites mark under 20% of resources cacheable (66% good LCP vs 72% at 80%+).
Across 65,509 WordPress sites, 38.8% mark 80%+ of subresources as cacheable (72% good LCP), 17.3% cache 50% to 79% (74% good LCP), and 35.9% cache under 20% (66% good LCP).
Shopify 8,573 stores 100% of Shopify stores cache at least 50% of subresources (96% good LCP at 80%+ cacheable).
Across Shopify storefronts, 61.3% mark 80%+ of resources as cacheable (96% good LCP) and 38.4% cache 50% to 79% (93% good LCP).
React & Next.js 9,570 sites React & Next.js sites caching under 20% of resources (9.5%) pass LCP at 64% vs 88% at 80%+ (24 points apart).
Across React sites, 58.3% cache 80%+ of assets (88% good LCP), 28.8% cache 50% to 79% (86%), and 9.5% cache under 20% (64% good LCP).
By Arjen Karel · 210,902 crawled sites (126,761 with phone Chrome field data, 206,258 sites with cacheable resource share, October 2026). How we measured.