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title: "Cookie Banners Cost 3.7 Points of LCP, Yet Those Sites Pass Core Web Vitals More Often - PageSpeed Matters"
description: "Cookie consent banners add a real loading cost, with good-LCP down 3.7 points on mobile. Yet the sites that run them pass Core Web Vitals more often overall, because consent tools cluster on better-built sites."
lang: en
json-ld:
---

[Cookie Banners Cost 3.7 Points of LCP, Yet Those Sites Pass Core Web Vitals More Often](https://www.pagespeedmatters.com/resources/data-studies/cookie-consent-banners-core-web-vitals)

Cookie consent banners add a real loading cost, with good-LCP down 3.7 points on mobile. Yet the sites that run them pass Core Web Vitals more often overall, because consent tools cluster on better-built sites.

Good loading (LCP) with and without a cookie banner (mobile)

Without a banner

68.9% 

With a banner

65.2% 

Source: PageSpeed Matters analysis of 9.5 million origins with CrUX field data, mobile 75th percentile, mid-2026.

On the one metric a banner actually touches, banner sites are behind. That 3.7-point gap is the honest, tool-attributable cost.

Where banner sites lose and win (mobile)

Good INP (banner ahead)

90% 

Good INP (no banner)

83.8% 

Good CLS (banner)

87.5% 

Good CLS (no banner)

88.3% 

Good LCP (banner behind)

65.2% 

Good LCP (no banner)

68.9% 

Source: PageSpeed Matters, mobile 75th-percentile field data, mid-2026. Values shown as with-banner versus without.

A well-built consent tool touches loading, not responsiveness. The INP gap is the site-quality confound in plain view.

Source: [Cookie Banners Cost 3.7 Points of LCP, Yet Those Sites Pass Core Web Vitals More Often - PageSpeed Matters](https://www.pagespeedmatters.com/resources/data-studies/cookie-consent-banners-core-web-vitals)