100.0% of Wix sites use unspecified cache HTTP cache TTL tiers, and 94% of those sites have a good LCP, against 94% of all Wix sites.
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
Sites with unspecified cache HTTP cache TTL tiers have a good LCP most often: 94%, against 94% of all Wix sites. Sites with short-TTL cache tiers have it least often, at 92%.
SitesGood, needs improvement, poor LCPMedian
All Wix sites5,33394%1.2s
Unspecified cache lifetime 100.0%5,33394%1.2s
Long TTL (> 30 days) 99.9%5,33294%1.2s
Medium TTL (1 - 30 days) 99.9%5,33294%1.2s
Cache-Control: immutable 99.9%5,33294%1.2s
Cache-Control: no-store 99.9%5,33194%1.2s
Cache-Control: no-cache 99.9%5,33194%1.2s
Short TTL (< 1 day) 47.9%2,57492%1.3s
GoodNeeds improvementPoorSites: with Chrome field data
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
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HTTP cache TTL tiers usage
Unspecified cache is the most used: 100.0% of Wix sites.
Sites using each option (sites can use more than one) 5,621 sites
Unspecified cache lifetime 100.0% Long TTL (> 30 days) 99.9% Medium TTL (1 - 30 days) 99.9% Cache-Control: immutable 99.9% Cache-Control: no-store 99.9% Cache-Control: no-cache 99.9%
Unspecified cache lifetime 100.0% Long TTL (> 30 days) 99.9% Medium TTL (1 - 30 days) 99.9% Cache-Control: immutable 99.9% Cache-Control: no-store 99.9% Cache-Control: no-cache 99.9% Short TTL (< 1 day) 47.9%
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
3
How HTTP cache TTL tiers affect the four LCP phases
Across the four LCP sub-parts in Chrome's field data, the largest gap between unspecified cache and short-TTL sits in time to first byte (TTFB): 419 ms median for unspecified cache against 471 ms for short-TTL. Overall median field LCP is 1.2s for unspecified cache (TTFB 419 ms, load delay 455 ms, load duration 137 ms, render delay 151 ms) versus 1.3s for short-TTL.
Median LCP phase breakdown (Chrome field p75) Load delay Median LCP
All Wix sites 3,945419 ms455 ms137 ms151 ms455 mslab 455 ms1.2s
Long TTL (> 30 days) 3,945419 ms455 ms137 ms151 ms455 mslab 455 ms1.2s
Unspecified cache lifetime 3,945419 ms455 ms137 ms151 ms455 mslab 455 ms1.2s
Cache-Control: no-store 3,944419 ms455 ms151 ms455 mslab 455 ms1.2s
Cache-Control: no-cache 3,945419 ms455 ms137 ms151 ms455 mslab 455 ms1.2s
Medium TTL (1 - 30 days) 3,945419 ms455 ms137 ms151 ms455 mslab 455 ms1.2s
Cache-Control: immutable 3,945419 ms455 ms137 ms151 ms455 mslab 455 ms1.2s
Short TTL (< 1 day) 1,871471 ms479 ms142 ms151 ms479 mslab 479 ms1.3s
TTFB Resource load delay Resource load time Element render delay
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
4
HTTP cache TTL tiers per framework
React sets the HTTP cache TTL tiers to unspecified cache on 100% of its sites, and 94% of React sites have a good LCP, against 94% of all sites.
FrameworkHTTP cache TTL tiers on its sitesGood LCP
All Wix sites 5,621 sitesUnspecified cache lifetime 100%Long TTL (> 30 days) 100%Medium TTL (1 - 30 days) 100%Cache-Control: immutable 100%Cache-Control: no-store 100%Cache-Control: no-cache 100%Short TTL (< 1 day) 48%94%
React 5,620 sitesCache-Control: immutable 100%Medium TTL (1 - 30 days) 100%Unspecified cache lifetime 100%Long TTL (> 30 days) 100%Cache-Control: no-store 100%Cache-Control: no-cache 100%Short TTL (< 1 day) 48%94% Unspecified cache lifetime Long TTL (> 30 days) Medium TTL (1 - 30 days) Cache-Control: immutable Cache-Control: no-store Cache-Control: no-cache Short TTL (< 1 day)
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
5
HTTP cache TTL tiers or the framework
Does the framework explain the HTTP cache TTL tiers difference?
Almost every site with unspecified cache HTTP cache TTL tiers is a React site, and almost every React site has unspecified cache HTTP cache TTL tiers, so the data can't tell unspecified cache HTTP cache TTL tiers and React apart.
How Cache-Control: immutable and long TTLs accelerate repeat views
Field Core Web Vitals combine first visits and repeat navigations from Chrome users. Sites that serve content-hashed static bundles with Cache-Control: immutable (99.9% of sites) achieve 94% good field LCP (1.2s median LCP), outperforming sites limited to short TTLs (47.9%, 92% good LCP) or no-store responses (99.9%, 94% good LCP).
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field dataBy Arjen Karel · corewebvitals.io/state-of-cwv
6
Understanding HTTP cache TTL tiers
Fingerprint static CSS, JavaScript, and font filenames and serve them with Cache-Control: public, max-age=31536000, immutable. While 99.9% of sites use long cache TTLs, only 99.9% include the immutable directive (94% good LCP), which prevents unnecessary 304 revalidation round-trips when users reload or navigate across pages.
The State of Web Vitals · October 2026 · Wix: 5,621 crawled sites · 5,333 with all devices field dataBy Arjen Karel · corewebvitals.io/state-of-cwv