Good Cumulative Layout Shift (CLS) Score

Description

The page has a good Cumulative Layout Shift (CLS) score, indicating stable layout during loading.

How to Fix

No action needed. Your page has good visual stability.

Detailed Analysis

The statement provided actually indicates a positive outcome rather than an SEO issue. A good Cumulative Layout Shift (CLS) score is a beneficial attribute for a webpage, signaling that the page content is stable and does not shift unexpectedly during loading. However, to fully understand and maintain a good CLS score, it's essential to dive into the details of CLS and its implications for SEO.

1. What Causes Cumulative Layout Shift (CLS)

CLS is a metric from Google's Core Web Vitals that measures visual stability. It represents the sum of all unexpected layout shifts that occur during the lifespan of a page. A layout shift occurs whenever a visible element changes its position from one rendered frame to the next.

Causes of Poor CLS:

• Unsized Media: Images or videos without dimensions can shift the content around them as the media is loaded.
• Dynamic Content: Ads, embeds, or iframes that are dynamically injected into a page can cause content to move.
• Web Fonts: Late-loading web fonts can cause text to reflow, leading to layout shifts.
• Unexpected UI Changes: Elements such as pop-ups, banners, or notifications that appear without user interaction can move existing content.
• Asynchronous Content Loading: Resources loaded asynchronously can cause elements to shift if they’re not accounted for properly.

2. Why It's Important

A good CLS score is crucial for user experience and SEO for several reasons:

• User Experience: Layout shifts can be frustrating for users, especially if they cause users to click on the wrong element due to unexpected movements.
• Accessibility: Unexpected shifts can disorient users, particularly those with disabilities or those using assistive technologies.
• SEO Rankings: Google considers Core Web Vitals, including CLS, as part of its page experience signals, which can influence search rankings.
• Conversion Rates: A stable page layout can lead to higher user satisfaction, engagement, and conversions.

3. Best Practices to Prevent Poor CLS

To maintain a good CLS score, follow these best practices:

• Define Size Attributes: Always set explicit width and height for images, videos, and other media to reserve space in advance.
• Use Aspect Ratio Boxes: For responsive images and embeds, use CSS to define aspect ratio boxes, preventing shifts when they load.
• Preload Fonts: Use the rel="preload" attribute to load web fonts early, minimizing layout shifts once fonts are applied.
• Allocate Space for Ads: Reserve a fixed space for ads or dynamic content to prevent unexpected shifts when they load.
• Use Transform Animations: Avoid layout-affecting animations. Use CSS transform and opacity for animations instead of properties that trigger reflows.
• Monitor and Optimize Third-party Code: Be mindful of third-party scripts and their impact on layout stability. Optimize or defer their loading if possible.

4. Examples of Good and Bad Cases

Good Case:

• Example: An e-commerce product page where images have defined sizes, ads have reserved spaces, and fonts are preloaded.
  • Outcome: The page loads smoothly without unexpected movements, providing a stable and predictable user experience.

Bad Case:

• Example: A news article page where images load without specified dimensions, causing text to jump as images appear.
  • Outcome: Users experience content shifts, leading to potential frustration, accidental clicks, and a negative perception of the website.

By understanding the causes of CLS, its importance, and implementing best practices, you can enhance your website's user experience and potentially improve its search engine rankings. Maintaining a good CLS score is an ongoing process that involves careful planning and optimization of page elements.