Web performance | MDN
Web performance is the objective measurements and the perceived user experience of load time and runtime. Web performance is how long a site takes to load, become interactive and responsive, and how smooth the content is during user interactions. Performance concerns questions like: Is scrolling smooth? Are buttons responsive? Do pop-ups load quickly and animate fluidly? The objective measurements include time to load, frames per second, and time to become interactive, and subjective experience means how long it feels like it takes for content to load.
The longer it takes for a site to respond, the more users will abandon the site. It is important to minimize the loading and response times and add additional features to conceal latency by making the experience as available and interactive as possible, as soon as possible, while asynchronously loading in the longer tail parts of the experience.
There are tools, APIs, and best practices that help us measure and improve web performance. We cover them in the following pages.
