Optimising User Experience With Core Web Vitals

iCrossing UK

Client: American Express

American Express’s slow homepage speed was hindering user experience, so it was clear we needed to define a clear strategy in order to improve page speed scores and provide a smooth and responsive interaction for users. To do this, we’d have to ensure the homepages met or surpassed Google’s passing threshold of 70%-page speed across both desktop and mobile.


After running a page speed report, we were able to highlight the highest priority areas and explored solutions that wouldn’t compromise the visuals and usability of the site. These included removing unused JavaScript, image optimisation, and multiple technical fixes at template level. To demonstrate positive change, we created a monthly report to monitor the impact of these optimisations on user experience. The results surpassed expectations, with a 48% and 37% uplift for desktop and mobile respectively since the start of the year. As a result, we also saw a 10% increase in SEO visits (2.9m) across all AmEx homepages.