What Is Cumulative Layout Shift (CLS)?
Cumulative Layout Shift (CLS) is a metric to measure unexpected layout shifts of visual elements on a webpage during its lifespan. It quantifies the visual stability of a page by calculating the sum of all individual layout shift scores.
The Importance Of Cumulative Layout Shift (CLS)
CLS assesses the extent to which content shifts on a webpage, impacting user experience, especially when users interact with elements or navigate through the site. High CLS values can lead to user frustration and negative perceptions of website reliability.
Best Practices For Cumulative Layout Shift (CLS)
Set dimensions for media elements: Specify dimensions for images, videos, and other media elements to reserve space and prevent layout shifts.
Avoid dynamically injected content: Ensure that content added dynamically does not cause abrupt layout changes that disrupt user interaction.
Load fonts with fallback options: Load fonts with fallback options to prevent text from shifting during font loading.
Delay JavaScript execution: Defer non-critical JavaScript execution to minimize its impact on layout stability.
Regularly monitor and address layout shifts: Continuously monitor CLS scores and promptly address any layout shift issues to maintain a stable user experience.
Key Aspects Of Cumulative Layout Shift (CLS)
User Experience: CLS directly impacts user experience by influencing the perceived stability and usability of a webpage.
Page Engagement: High CLS values can lead to user frustration and disengagement, affecting bounce rates and conversion rates.
Performance Optimization: Optimizing CLS enhances the overall page experience and contributes to improved user satisfaction and retention.
Summary
CLS measures the unexpected layout shifts of visual elements on a webpage. It is crucial for maintaining visual stability and user satisfaction. Optimizing dimensions for media elements, managing dynamically injected content, and monitoring layout shifts are essential for improving CLS and overall user experience.
