Total page weight on React sites

Sites with under 1.2 MB of total page weight total page weight have a good LCP most often: 93%, against 79% of all React sites. Sites with over 5 MB of total page weight page weight have it least often, at 66%.

1.2 to 2.5 MB of total page weight is the most used: 41.8% of React sites. Under 1.2 MB of total page weight is 14.1% of React sites.

Across the four LCP sub-parts in Chrome's field data, the largest gap between under 1.2 MB of total page weight and over 5 MB of total page weight sits in time to first byte (TTFB): 305 ms median for under 1.2 MB of total page weight against 861 ms for over 5 MB of total page weight. Overall median field LCP is 1.0s for under 1.2 MB of total page weight (TTFB 305 ms, load delay 254 ms, load duration 135 ms, render delay 157 ms) versus 2.0s for over 5 MB of total page weight.

On Wix, 54% of sites use 1.2 to 2.5 MB of total page weight total page weight, and 92% of Wix sites have a good LCP, against 79% of all sites. On WordPress, 40% of sites use over 5 MB of total page weight, and 66% of WordPress sites have a good LCP.

PlatformTotal page weight on its sitesGood LCP

All React sites 9,570 sites1.2 to 2.5 MB total page 42%2.5 to 5 MB total page 24%Over 5 MB total page 20%Under 1.2 MB total page 14%79%

Wix 5,824 sites1.2 to 2.5 MB total page 54%2.5 to 5 MB total page 19%Under 1.2 MB total page 15%Over 5 MB total page 12%92%

WordPress 2,342 sitesOver 5 MB total page 40%2.5 to 5 MB total page 36%1.2 to 2.5 MB total page 20%66%

1.2 to 2.5 MB total page 2.5 to 5 MB total page Over 5 MB total page Under 1.2 MB total page

Does the platform explain the total page weight difference?

On Wix, 100% of sites with under 1.2 MB of total page weight total page weight have a good LCP, against 95% of Wix sites with 1.2 to 2.5 MB of total page weight. Within Wix, sites with under 1.2 MB of total page weight and 1.2 to 2.5 MB of total page weight have a good LCP about equally often. On WordPress, 81% of sites with 1.2 to 2.5 MB of total page weight total page weight have a good LCP, against 66% of WordPress sites with 2.5 to 5 MB of total page weight. Within WordPress, sites with 1.2 to 2.5 MB of total page weight have a good LCP more often.

How total page weight compounds across cellular connections

Even with HTTP/2 and HTTP/3 multiplexing, transferring several megabytes of scripts, stylesheets, fonts, and images saturates mobile downlink bandwidth and delays critical rendering resources. Across 1,346 sites (14.1%) under 1.2 MB total transfer, 93% pass field LCP (1.0s median), falling to 66% (1.9s median) on the 20.5% (1,958) exceeding 5 MB.