Shopify uncompressed text responses and the Core Web Vitals

Sites with full text compression text compression coverage have a good LCP most often: 98%, against 96% of all Shopify sites. Sites with uncompressed text responses text compression have it least often, at 95%.

Uncompressed text responses is the most used: 68.7% of Shopify sites. Full text compression is 31.3% of Shopify sites.

Across the four LCP sub-parts in Chrome's field data, the largest gap between full text compression and uncompressed text responses sits in resource load delay: 536 ms median for full text compression against 609 ms for uncompressed text responses. Overall median field LCP is 1.2s for full text compression (TTFB 365 ms, load delay 536 ms, load duration 214 ms, render delay 254 ms) versus 1.4s for uncompressed text responses.

On jQuery, 74% of sites use uncompressed text responses text compression coverage, and 94% of jQuery sites have a good LCP, against 96% of all sites. On Vue, 76% of sites use uncompressed text responses, and 95% of Vue sites have a good LCP.

FrameworkText compression coverage on its sitesGood LCP

All Shopify sites 8,246 sitesHas uncompressed text 69%All text compressed 31%96%

Vue 933 sitesHas uncompressed text 76%All text compressed 24%95%

jQuery 3,153 sitesHas uncompressed text 74%All text compressed 26%94%

Has uncompressed text All text compressed

Does the framework explain the text compression coverage difference?

On jQuery, 96% of sites with full text compression text compression coverage have a good LCP, against 93% of jQuery sites with uncompressed text responses. Within jQuery, sites with full text compression have a good LCP more often. On Vue, 98% of sites with full text compression text compression coverage have a good LCP, against 94% of Vue sites with uncompressed text responses. Within Vue, sites with full text compression and uncompressed text responses have a good LCP about equally often.

Where uncompressed text responses slip through on modern web stacks

Almost no server intentionally disables compression globally. Instead, uncompressed text responses slip through narrow MIME-type allowlists (forgetting image/svg+xml or application/json in nginx or Apache) or come from third-party API and widget endpoints that bypass the primary CDN. Across 2,580 sites (31.3%) that compress every text response, good LCP reaches 98% (1.2s median, 365 ms TTFB), whereas the 5,666 sites (68.7%) shipping at least one uncompressed text payload drop to 95% good LCP (1.4s median, 400 ms TTFB).