CLS (Cumulative Layout Shift)

What is CLS?

CLS (Cumulative Layout Shift) is one of the three Core Web Vitals, alongside LCP and INP. It measures how much the content of a page unexpectedly shifts while it loads. A low score means a stable page. According to Google, a score of 0.1 or lower is good, measured for at least 75 percent of page visits.

Why is CLS important?

• A nicer experience: nobody wants to tap the wrong button because the page jumped.
• Page experience: Core Web Vitals are among the signals Google uses for page experience, although content still weighs more.
• Less frustration: a stable page can reduce drop-off at checkout.

Examples of CLS

• An image without fixed dimensions pushes the text down as soon as it loads.
• A cookie banner that appears late and shoves the page down.
• An ad that suddenly takes up space above a button.

How do you improve CLS?

Give images, videos and ads a fixed width and height so the space is reserved in advance. Do not insert content above existing content, and load fonts in a way that does not cause shifts. Measure your score in PageSpeed Insights. This is part of technical SEO.