Leaflet.org

Over 50 thousand developers visit DavidWalshBlog every month from around the world to learn JavaScript tricks and fix problems in their code. Unfortunately, some of them have a slow experience on the site. David tracks the performance of his Core Web Vitals and overall performance with Request Metrics. Recently, we noticed that his CLS performance score was trending pretty slow for both desktop and mobile users. Wait, what is CLS? Cumulative Layout Shift (CLS) is one of the Core Web Vital performance metrics. It doesn’t measure load time directly, instead it measures how much a page shifts while it is being loaded. You’ve definitely seen this and been annoyed by it. These shifts... more →