LCP image origin on React sites
Serving the hero image from your own domain versus an external image CDN: how a separate connection adds 143 ms of resource load delay (478 ms vs 335 ms) and when <link rel="preconnect"> pays it back.
72.0% of React sites use third-party LCP image hosting, and 88% of those sites have a good LCP, against 79% of all React sites.
LCP pass rate
Sites with third-party LCP image hosting have a good LCP most often: 88%, against 79% of all React sites. Sites with first-party image hosting have it least often, at 71%.
LCP image hosting usage
Third-party is the most used: 72.0% of React sites.
Where third-party LCP images lose and win time: the four LCP phases
Across the four LCP sub-parts in Chrome's field data, the largest gap between third-party and first-party sits in time to first byte (TTFB): 403 ms median for third-party against 1016 ms for first-party. Overall median field LCP is 1.3s for third-party (TTFB 403 ms, load delay 478 ms, load duration 201 ms, render delay 147 ms) versus 1.8s for first-party.
LCP image origin combined with preconnect and priority hints
Combining third-party with Highprio reaches 92% good LCP across 381 sites (481 ms median load delay). At the other end, first-party paired with None sits at 70% across 579 sites (371 ms median load delay).
| Image origin | No priority hint | <link rel="preconnect"> | fetchpriority="high" | <link rel="preload"> |
|---|---|---|---|---|
| Same-origin / first-party | 70% 1,613 sites | few sites | 75% 295 sites | 77% 100 sites |
| Third-party domain | 85% 1,852 sites | 73% 238 sites | 92% 3,057 sites | few sites |
LCP image hosting per platform
Wix sets the LCP image hosting to third-party on 100% of its sites, and 92% of Wix sites have a good LCP, against 79% of all sites. WordPress sets the LCP image hosting to first-party on 93% of its sites, and 66% of WordPress sites have a good LCP.
Wix 4,215 sitesThird-party domain 100%92%
WordPress 1,816 sitesSame-origin / first-party 93%66%LCP image origin or the platform
Does the platform explain the LCP image hosting difference?
On WordPress, 68% of sites with third-party LCP image hosting have a good LCP, against 65% of WordPress sites with first-party. Within WordPress, sites with third-party and first-party have a good LCP about equally often.
Why third-party hero images pay a connection tax in resource load delay
When the LCP image lives on the same origin as the HTML document, the browser reuses the open HTTP/2 or HTTP/3 connection immediately. When the image sits on a separate domain, Chrome must resolve DNS, complete a TCP or QUIC handshake, and negotiate TLS before requesting the first image byte. That handshake shows up directly in Chrome's field data: third-party LCP images have a 478 ms median resource load delay compared with 335 ms for first-party images (143 ms slower to start), even though dedicated image CDNs finish the download slightly faster (201 ms vs 122 ms).
Understanding LCP image origin
Serve the LCP image from the same origin as your HTML document whenever possible, so the image rides the already-open HTTP/2 or HTTP/3 connection. If you use a dedicated image CDN on a separate domain (72.0% of audited sites), add <link rel="preconnect" href="https://your-cdn.example" crossorigin> in the document <head>. In Chrome's field data, third-party LCP images without a hint wait 471 ms before the download starts, while pairing a third-party image with <link rel="preconnect"> cuts resource load delay to 406 ms and lifts good LCP from 85% to 73%.
By Arjen Karel · 9,570 crawled React sites (1,979 with desktop Chrome field data, 7,170 sites with LCP image hosting, October 2026). How we measured.