PageSpeed Insights is a free tool developed by Google that analyzes the performance of web pages. It provides insights into how quickly a page loads and offers suggestions for improving its speed. The tool evaluates both mobile and desktop versions of a site, giving users a score from 0 to 100, with higher scores indicating better performance. The analysis includes metrics such as First Contentful Paint and Time to Interactive, which help identify areas that may be slowing down a website. By following the recommendations provided, website owners can enhance user experience and potentially improve their search engine rankings.