web.dev: Core Web Vitals Business-Impact Case Studies
A recurring case-study series on web.dev (Google’s developer-education site), each one pairing a real company’s Core Web Vitals optimization work with the business metrics (conversion, revenue, bounce rate) that followed.
License: CC BY 4.0 — confirmed via the page footer (“the content of this page is licensed under the Creative Commons Attribution 4.0 License”) on every page cited here.
Key points
- Vodafone Italy — a 31% LCP improvement (server-side rendering, less render-blocking JS, image optimization) produced +8% sales, +15% lead-to-visit conversion, +11% cart-to-visit conversion.
- Rakuten 24 — JS/image optimization and CLS fixes drove +53.37% revenue per visitor, +33.13% conversion rate, +15.20% average order value.
- redBus — reducing Interaction to Next Paint from ~900ms to ~350ms (debounced scroll handlers, smaller batch sizes, local-then-synced input state) produced a 7% increase in sales.
- Renault — across 10M+ visits in 33 countries, each 1-second LCP improvement correlated with a 13% increase in conversions and a 14-percentage-point drop in bounce rate.
- Swappie — a mobile-performance focus raised mobile revenue 42% and mobile conversion rate 10 percentage points (24%→34%).
- QuintoAndar — a 2021 Core Web Vitals + Next.js migration produced +5% conversion, +87% pages/session, -46% bounce; a 2025 follow-up INP-focused effort (“Code Yellow”) added +36% conversions year-over-year.
- Netzwelt — a broader Core Web Vitals initiative increased ad revenue 18%, page views 27%, and cut bounce rate 50%.
- Agrofy — a 70% LCP improvement correlated with a drop in load-abandonment from 3.8% to 0.9%.
- Deloitte Digital’s “Milliseconds Make Millions” — a cross-industry study of 37 brands and 30M sessions found a 0.1-second mobile speed improvement raised retail conversion 8.4%, travel booking rate 10%, and lead-gen form submissions 21.6%.
- iCook — a 15% Cumulative Layout Shift improvement (fixed ad-slot sizing, deferred non-critical JS) raised ad revenue 10%.
- Mynet — combining AMP (4x faster loads) with a PWA raised ad revenue per pageview 25%, time on site 43%, and pageviews per session 34%.
- Truebil — a PWA rebuild (code splitting, hybrid caching, installation prompts) raised conversions 61% and revenue-to-marketing spend 80%.