Core Web Vitals explained

Three measurements Google uses to judge how fast your page feels. They measure experience, not technology.

Loading the main content

How quickly does the largest visible element appear? Usually an image or a heading. It is the first moment your page looks usable.

Responsiveness

How long between a click and a visible reaction? A heavy script blocking the browser makes your page feel broken even when everything has loaded.

Visual stability

Does the layout jump while loading? An image without set dimensions or a late-appearing banner pushes content around, and the visitor clicks the wrong thing.

How to improve them

Images are the most common cause of all three. External scripts come next. Finally, reserve space in advance for anything that loads later.

Measure with real data

A lab test on a fast connection is not what your visitor experiences. Look at field measurements.