Table of Contents Introduction What is Cumulative Layout Shift? Why is it important? Definition When Does it End? Single Page Apps (SPAs) IFRAMEs How to Improve It How to Measure It RUM Example Code Attribution Fallbacks Browser Support Gotchas Open-Source / Free RUM Commercial RUM Synthetic Free Synthetic Developer Tools Commercial Synthetic Monitoring Tools RUM […] The post Cumulative Layout Shift in Practice first appeared on NicJ.net.| NicJ.net
UserTiming is a modern browser performance API that gives developers the ability the mark important events (timestamps) and measure durations (timestamp deltas) in their web apps. For an in-depth overview of how UserTiming works, you can see my article UserTiming in Practice or read Steve Souders’ excellent post with several examples for how to use […] The post Compressing UserTiming first appeared on NicJ.net.| NicJ.net
At SOASTA, we’re building tools and services to help our customers understand and improve the performance of their websites. Our mPulse product utilizes Real User Monitoring to capture data about page-load performance. For browser-side data collection, mPulse uses Boomerang, which beacons every single page-load experience back to our real time analytics engine. Boomerang utilizes NavigationTiming […] The post Compressing ResourceTiming first appeared on NicJ.net.| NicJ.net
The visibilitychange event is fired at the document when the contents of its tab have become visible or have been hidden.| MDN Web Docs
The load event is fired when the whole page has loaded, including all dependent resources such as stylesheets, scripts, iframes, and images, except those that are loaded lazily. This is in contrast to DOMContentLoaded, which is fired as soon as the page DOM has been loaded, without waiting for resources to finish loading.| MDN Web Docs
The navigator.sendBeacon() method asynchronously sends an HTTP POST request containing a small amount of data to a web server.| MDN Web Docs
You cannot rely on pagehide, beforeunload, and unload events to fire on mobile platforms. This is not a bug in your favorite browser; this is due to how all mobile operating systems work. Use Page Visibility API.| www.igvita.com
AcceptFilter Directive| httpd.apache.org