In the first quarter of 2021, a global invoicing software company seeking an audit and consultancy for mobile core web vitals ahead of Google’s mobile page experience update in June partnered with

This international software company helps establishments and consultants with a wide variety of financially related services, such as payment scheduling, invoicing, and payment reminders. Additionally, their software product also offers the ability of integrated time tracking.


The team at approached this project by completing a comprehensive core web vital audit. Analysing each URL on the invoicing software site using the Lighthouse API to pull through each First Input Delay, Content Layout Shift, and Largest Contentful Paint scores. 

 We worked alongside the companies internal marketing and development team to focus on their high priority URLs. This helped us to  further understand what elements on the page were hampering each of the core web vital metrics, such as the hero image increasing the pages FID and LCP to download invoicing template buttons, causing a CLS.

This was then used to help formulate each core web vital recommendation for the priority URLs, which were then transferred into a Fibonacci prioritization sheet (in line with Agile development methodology) so we could receive input from the companies web developers and determine which of the solutions would require more resources to what their impact could be. 

Due to the core web vitals scores being negatively impacted site wide by the template the website was using the company opted to overhaul the site with a new theme. SALT provided consultancy of the WordPress themes they were considering, as well as running additional core web vital audits in the staging environment. 

This resulted in the sites overall core web vital performance significantly improving for each metric by an average of 63%.


  • In-depth core web vital auditing and troubleshooting
  • Technical analysis


  • FID improved by 45%
  • LCP improved by 50%
  • CLS improved by 94%