Explore the intricacies of performance measurement in web development through this insightful conference talk from Vue.js Live 2021. Delve into the world of Lighthouse, Chrome User Experience Report (CrUX), and Core Web Vitals to gain a comprehensive understanding of how these tools function and their significance in assessing website performance. Learn to interpret performance metrics such as Largest Contentful Paint, First Input Delay, and Cumulative Layout Shift, and discover the differences between lab and field data. Gain practical knowledge on how to effectively use these tools, avoid common misconceptions, and draw accurate conclusions from the data to optimize your web applications. By the end of this talk, acquire the skills to make informed decisions about performance optimization and effectively communicate results to both technical and non-technical stakeholders.