Google’s Core Web Vitals metric for visual stability. Direct SEO ranking factor since 2021.
Are you tired of seeing your website content jump around unexpectedly when it loads? That jarring experience is more than just annoying for your visitors; it actively harms your SEO.
Google prioritizes a great user experience, and a high Cumulative Layout Shift (CLS) score tells them your site is unstable, which can directly affect your search rankings. Do not worry, because you are about to get simple, actionable tips to fix it and make Google—and your users—love your site.
What is Cumulative Layout Shift (CLS)?
Cumulative Layout Shift (CLS) is one of the three Core Web Vitals, which are key Google metrics for measuring page experience. CLS measures the total score of all unexpected shifts of visible content that happen as your page loads and during the user’s visit. A layout shift occurs when an element changes its start position from one rendered frame to the next, causing the content below it to move.
A good CLS score is 0.1 or less, meaning your page feels stable and professional to a user. Unexpected shifts often cause people to accidentally click the wrong thing, leading to a very poor user experience and a high bounce rate.
How Google Calculates the CLS Score
Google calculates the score using a formula that looks at two things: how much of the screen shifts and how far it moves. The layout shift score is the product of the Impact Fraction and the Distance Fraction. The Impact Fraction shows the area of the viewport affected by the shift, while the Distance Fraction measures the greatest distance the unstable element moved relative to the viewport size.
For example, if a large element shifts a long distance, the score is high; a small element shifting a short distance results in a low score. You are aiming for a low score because a smooth, stable page is a fast page in the user’s mind.
What Causes a High Cumulative Layout Shift?
A few common culprits are responsible for most bad Cumulative Layout Shift scores across the web.
The Usual Suspects
First, images and videos without dimensions cause issues because the browser does not know how much space to reserve before they load, making the content jump. Second, dynamically injected content like ads, embeds, and iframes often load late and push existing elements down the page. Third, issues with web fonts, such as a Flash of Unstyled Text (FOUT), cause the text to briefly switch fonts, which shifts the layout. You must proactively fix these issues to pass the Core Web Vitals assessment.
Cumulative Layout Shift Across Different CMS Platforms
The solution for fixing Cumulative Layout Shift often depends on what platform you are using to build your website.
WordPress
On WordPress, late-loading scripts from plugins and themes are the most frequent cause of CLS. You are advised to use modern image formats and ensure your images and videos always have set width and height attributes. Consider optimizing your font loading with a plugin that adds font-display: swap to your CSS for better stability.
Shopify
For Shopify stores, you must pay attention to third-party apps like review widgets or pop-ups that inject content without reserving space. Inspect these elements and use CSS to assign a min-height value as a placeholder where dynamic content is expected to appear. Making sure your product images have a clearly defined aspect ratio is also critical.
Wix and Webflow
Wix and Webflow users typically have fewer core code issues, but dynamic elements still need care. When adding videos or embedded social posts, you are responsible for making sure you reserve space for them with placeholder elements. In Webflow, you can often control CSS directly to apply fixes like aspect ratio boxes for images.
Custom CMS
With a custom CMS, you are in complete control, so your developers must implement best practices from the start. They must use the CSS transform property for animations instead of properties like top or left, which trigger a layout shift. Ensure your code reserves all necessary space for images and ads before they finish loading.
CLS Impact by Industry: What You Must Fix
The layout shifts that affect your CLS score can impact various industries differently, but the solution remains the same: visual stability.
Ecommerce (Shopify, Custom Stores)
In ecommerce, a shifting product gallery or an “Add to Cart” button that moves can directly cost you sales. You must make sure all product images, thumbnails, and sales badges are in place immediately without causing content to jump. Prioritizing stability on your checkout and product pages is non-negotiable.
Blogs and News Sites (WordPress)
On a blog, late-loading ads placed inside an article are the biggest CLS villain. An unexpected shift can make a user lose their place while reading, which causes them to immediately leave the site. You are advised to use reserved placeholder space for all advertisements to avoid content reflow.
Local Businesses and Service Websites (Wix, WordPress)
These sites often embed maps or social feeds, which must be loaded correctly. You can pre-calculate the final size of the map or embed and apply a min-height to its container to hold the space. Do not let your contact form suddenly pop into view and push down your phone number or business address.
SaaS and Tech Companies (Webflow, Custom)
For SaaS, unexpected shifts in pricing tables or sign-up forms feel unprofessional and erode trust. You are expected to use transitions and animations that do not trigger layout recalculations, which means using transform animations for visual effects. Your page must appear flawless to maintain a cutting-edge image.
Your CLS Action Plan: Simple Steps to a Better Score
Improving your Cumulative Layout Shift is simpler than you think when you follow a clear plan.
First, run your website through Google’s PageSpeed Insights tool to see your current CLS score and identify the shifting elements. Next, you must define explicit width and height attributes for all images and videos, or use the CSS aspect-ratio property to reserve the correct space. For all third-party embeds, you should use a placeholder with a fixed min-height until the final content loads, preventing unexpected page jumps. By taking these actions, you are directly improving user experience and securing a better position in Google’s search results. Do not delay, as your SEO ranking is counting on your visual stability!
Frequently Asked Questions (FAQ)
What is a good Cumulative Layout Shift (CLS) score?
A good Cumulative Layout Shift score is 0.1 or lower as measured by Google’s Core Web Vitals. You are aiming for a score as close to 0 as possible, because this indicates a smooth and stable browsing experience for your users.
How does Cumulative Layout Shift affect my SEO ranking?
CLS is a direct part of Google’s Core Web Vitals, which is a key ranking factor for search results. A high Cumulative Layout Shift score signals a poor user experience, which can cause Google to lower your site’s ranking and reduce your organic traffic.
What are the most common causes of a high CLS score?
The most common causes are images or videos without set width and height attributes, which cause the content to jump when they load. Other major culprits include late-loading ads and embeds and web font issues that cause the text to briefly change size or style.
How can I check my website’s Cumulative Layout Shift score?
You are able to check your website’s Cumulative Layout Shift score using free tools like Google PageSpeed Insights or the Core Web Vitals report in Google Search Console. These tools will show you the score for both mobile and desktop users.
Should I use min-height for my dynamic content containers?
Yes, you are strongly advised to use min-height on containers where dynamic content, like ads or embedded posts, is going to load. This technique holds space for the content, preventing other elements from shifting when the dynamic content finally appears, significantly lowering your CLS.
