Grafana k6 browser and Google Lighthouse are tools used to assess web performance, each with distinct functionalities and methods of testing. The k6 browser module, part of Grafana k6 OSS, simulates user interactions to gather frontend performance metrics, allowing for a hybrid testing approach that combines browser and protocol-level scripts. It provides insights into user experience by measuring metrics such as First Input Delay (FID), which requires real user interaction. Conversely, Google Lighthouse is an open-source tool that evaluates overall website quality, including performance, accessibility, and SEO, generating audits and suggestions for improvements. Lighthouse primarily uses lab data, making it ideal for early diagnostics, but it doesn't measure FID due to its focus on initial page load analysis. Both tools report on Google Web Vitals, though Lighthouse additionally tracks metrics like Speed Index. Despite their differences, combining the use of both tools with additional field data sources, such as PageSpeed Insights, enhances the accuracy of web performance evaluations by capturing real user experiences.