Top 1,000,000: Loading Speed

Web performance can directly impact business metrics like conversion and user happiness. This report analyzes various performance metrics in the lifecycle of a loading page including those used by many modern progressive web apps.

First Contentful Paint

The number of seconds from the time the navigation started until the page's primary content appears on the screen.

Time to Interactive

The number of seconds from the time the navigation started until the CPU had at least 5 seconds of quiescence. This metric comes from Lighthouse. Read more about First Interactive and First Consistently Interactive.

DOMContentLoaded

The number of seconds from the time the navigation started until the initial HTML document has been completely loaded and parsed. See the DOMContentLoaded event on MDN for more info.

onLoad

The number of seconds from the time the navigation started until the document and all of its dependent resources have finished loading. See the load event on MDN for more info.

JavaScript Boot-up Time

The amount of CPU time each script consumes per page. This metric comes from Lighthouse.

See also: State of JavaScript

Speed Index

How quickly the contents of a page are visibly populated. This metric comes from WebPageTest and differs slightly from the Lighthouse version (which was based on this).