How Renault improved its bounce and conversion rates by measuring and optimizing Largest Contentful Paint
The team analyzed data from 10 million visits on its landing pages and found a strong correlation between Largest Contentful Paint and conversion rate.
Groupe Renault is a French multinational automobile manufacturer with a presence in over 130 countries. For an automotive group such as Renault, performant brand sites driving more user engagement and conversions mean more business. All of its brand sites aim at providing the best user experience at scale while maintaining flexibility of content and features for localized sites. In this context, performance monitoring is a key stake for the customer experience team which is in charge of developing and maintaining the global platform.
Measuring the business impact of Core Web Vitals #
Measurement in Google Analytics #
Working with fifty-five, its global data partner, Renault set up the web-vitals library, which allows sending to Google Analytics all the Web Vitals metrics from real users in a way that accurately matches how they're measured by Chrome and reported to other Google tools.
The following analysis showcases a dataset captured using these tools over four months between December 2020 and March 2021.
Optimized LCP strongly correlates with user engagement and business metrics #
The teams have identified a particularly strong correlation between a low Largest Contentful Paint (LCP) and favorable bounce rates and conversion rates, shown in the visualization below.
The dataset captures over 10 million visits in 33 countries over four months and shows how lower LCP measures correlates with:
- Lower bounce rates
- More conversions (lead forms completed)
Interestingly, as the website runs as a Single Page Application (SPA), all these measures are captured on landing pages only. The data shows that it is worth optimizing the website until the LCP reaches below 1 second. The group's brand sites can never be too optimized!
This dataset not only shows the negative correlation between LCP and business metrics, but also highlights performance discrepancies among the best performing landing pages. In the context of this website, getting LCP under 1 second leads to large increases in conversions and reductions in bounce.
Eja Rakotoarimanana, Consultant, fifty-five
1 second LCP improvement can lead to a 14 percentage points (ppt) decrease in bounce rate and 13% increase in conversions.
|1 second LCP improvement||Result|
|LCP around 1 s||+13% CVR|
|LCP under 1.6 s||-14 ppt bounce rate|
|LCP above 1.6 s||-5 ppt bounce rate|