How to Improve Cumulative Layout Shift (CLS)?

Improving Cumulative Layout Shift starts with stabilising everything users see first. When images, ads, and UI elements load within a defined space, the page feels calm rather than jumpy. Fixing CLS is about reducing surprises, not just for browsers, but for humans who expect the screen to stay exactly where it belongs.

What is CLS?

Cumulative Layout Shift, more commonly referred to as CLS, is a Core Web Vitals metric that evaluates how visually stable a webpage feels as it loads. If you’ve ever tried to click a button only to watch it suddenly jump because something above it loaded late, you’ve experienced what CLS measures.

At its simplest, CLS is the score that reflects how much the visible elements on a page move as everything loads (images, banners, fonts, widgets, ads, or scripts). 

When brands talk about digital performance today, CLS is one of the biggest concerns. It directly affects user trust, engagement, and conversions. That’s exactly why many brands are now trying to understand how to improve CLS score, how to prevent layout shifts in web pages, and how to improve page stability for better CLS.

Why Layout Shifts Happen Before You Even Realise It

Most CLS problems stem from unpredictable rendering images without defined dimensions, third-party elements loading whenever they feel like it, or UI components that rearrange the page at the last second. All of these break visual stability, which in turn affects user experience and conversions. If you want better page stability for better CLS, you must control these triggers at their source.

How Does CLS Impact SEO Score?

CLS has a direct impact on search performance because it is an official Google ranking factor within Core Web Vitals. When a user lands on a website that jumps unpredictably, their experience feels frustrating. They may abandon the page prematurely, send negative engagement signals, and harm your overall SEO health.

Search engines consider stability essential because it represents usability and accessibility, basically a layout that does not shift, and does not confuse. The smoother the experience, the higher your chances of ranking well.

Websites with good CLS typically enjoy:

• Better organic visibility
  
• Higher engagement and longer session times
  
• Improved conversion rates
  
• Lower bounce rates
  
• Better ad viewability and monetisation potential
  

This is where understanding how to fix layout instability, how to reduce layout shifts, and how to optimise CLS score becomes vital to long-term SEO growth.

What Defines a Good CLS Score?

A good CLS score is any score of 0.1 or lower. At this level, layout movements are minimal and barely noticeable to the user. The browsing experience feels natural, predictable, and stable.

Good CLS typically indicates that:

• All images have defined dimensions
  
• Ads and embeds reserve space properly.
  
• Web fonts are preloaded or optimised.
  
• Scripts do not reposition visible elements.
  
• Animations are controlled and intentional.
  

Sites aiming to improve CLS or reduce layout shifts benchmark themselves against this threshold. Maintaining this score requires consistent performance monitoring, especially across device types, network conditions, and real user behaviour.

What Defines a Bad CLS Score?

A CLS score of 0.25 or more is considered poor. At this level, users often experience jerky, unpredictable page movements. Buttons jump, text shifts, and impressions break down.

A poor score usually means:

• Multiple elements load without a predetermined space
  
• Ads are shifting dynamically.
  
• Pages rely heavily on lazy loading without proper container handling.
  
• Fonts are not preloaded.
  
• DOM elements are heavily altered after rendering
  

When this happens, websites usually experience a drop in both user engagement and SEO performance. This is when teams urgently search for how to improve CLS score, how to reduce layout shifts, and how to fix CLS issues.

How To Improve CLS Score : Fix the CLS Issues

1. Always Set Width & Height for All Images

One of the easiest and strongest solutions.

When you define explicit dimensions for an image, the browser allocates exact space before the image loads. This prevents unexpected jumps.

What to do:

• Add width and height attributes to every image tag.
  
• If images are responsive, allow the browser to auto-scale via CSS while maintaining the aspect ratio.
  

Example:<img src=”hero-banner.jpg” width=”1600″ height=”600″ alt=”Banner”>

2. Reserve Space for Ads, Embeds & Iframes

Ads are among the biggest contributors to poor CLS scores.

What to do:

• Declare fixed-size containers for ads.
  
• Provide fallback placeholders.
  
• Use responsive ad units with stable ratio boxes.
  
• Avoid collapsing empty ad slots.
  

Example:<div style=”width: 300px; height: 250px;”>  <!– Ad code here –></div>

3. Preload Web Fonts and Use Font-Display Settings

Fonts can cause major layout changes if not optimised.

Best practices:

• Preload the most critical fonts.
  
• Use font-display: optional, font-display: swap, or similar strategies.
  
• Serve variable fonts to reduce file requests.
  

Why this matters:
Web fonts impact CLS more than teams realise. A sudden text re-render can push boxes, headers, and navigation items out of alignment. This step directly supports to improve page stability for better CLS.

4. Avoid Adding Content Above Existing Content After Load

This includes:

• Cookie banners
  
• Promo bars
  
• “Chat now” widgets
  
• Push notification requests
  
• Dynamic headers
  

Fix:
Insert such elements at the end of the DOM or use overlays that do not push content down.

5. Use Skeleton Screens or Placeholder Boxes

Skeleton loaders make it easier for the browser to allocate space during render.

Example:<div class=”skeleton skeleton-image”></div>

6. Optimise Lazy Loading Carefully

Lazy loading boosts performance but can harm CLS if not implemented correctly.

To optimise:

• Keep image containers fixed in height.
  
• Lazy load below-the-fold assets only.
  
• Do not lazy-load hero banners.
  
• Use aspect-ratio CSS where possible.
  

Example:.image-box {  aspect-ratio: 16 / 9;}

7. Stabilise Dynamic Elements & Carousels

Sliders, feeds, and carousels often resize content based on JS execution.

Checklist:

• Declare fixed container height.
  
• Load the first slide content synchronously.
  
• Avoid resizing slides after load.
  
• Preload thumbnails.
  

8. Reduce DOM Manipulation by Scripts

When scripts rearrange elements post-load, they create instability.

Strategies:

• Minify and defer non-critical scripts.
  
• Avoid injecting DOM elements above visible content.
  
• Move less-critical components to later load phases.
  

This helps reduce layout shifts significantly.

9. Optimise CSS Delivery

Slow or fragmented CSS forces browsers to re-render layouts.

Best practices include:

• Inline critical CSS
  
• Preload main stylesheets
  
• Avoid large unused CSS libraries.
  
• Use modular CSS
  
• Test with multiple screen sizes
  

10. Provide Responsive Media Aspect Ratios

Video thumbnails, hero banners, and embedded players all benefit from aspect-ratio rules.

Example:.video-container {  aspect-ratio: 16/9;}

11. Manage Third-Party Scripts with Precision

Third-party scripts include:

• Social sharing widgets
  
• Analytics injections
  
• Commenting systems
  
• Chat assistants
  
• Personalisation engines
  

Its mitigation steps:

• Load them asynchronously
  
• Reserve space for injected elements
  
• Remove unnecessary JS
  
• Initialise heavy components after interaction
  

12. Use CSS Transformations for Animations

If animations push content around, CLS increases. Use transform, not top, left, margin, or padding. Transforms do not trigger layout recalculations.

13. Fix CLS in WordPress Using Plugins & Manual Tweaks

Many WordPress sites struggle with CLS due to theme-level issues, but you can solve it by

• Disabling unused widgets
  
• Replacing heavy plugins
  
• Using performance plugins like Perfmatters or WP Rocket
  
• Preloading fonts & critical CSS
  
• Lazy loading responsibly
  
• Fixing image sizes in the Media Library
  
• Add custom CSS for aspect ratios
  

These fixes support both optimise CLS score and fix CLS issues.

Designing a Stable Visual Hierarchy: A Clear Action Plan

• Start with a layout blueprint where every element has a defined space. This alone helps prevent layout shifts in web pages because the browser isn’t left guessing.
  
• Use container-based structures and CSS containment. These are best practices to prevent CLS and improve page experience, especially when multiple elements load at different speeds.
  
• Assign predictable dimensions to images, videos and banners. This is the core of how to optimise images and ads to improve CLS score, because you reserve the exact space they’ll need.
  
• Build scaffolding for content blocks so the layout stays consistent even before assets load. This step directly helps reduce layout shifts and keeps your visual hierarchy steady.
  
• Stabilise the areas above the fold first. Doing this helps improve page stability for better CLS, since these are the elements users see first and judge the site by.
  
• Treat CLS fixes as foundation work, not patches. When the page feels anchored from the start, it becomes easier to fix CLS issues holistically instead of chasing isolated problems later.
  
• Keep your structure simple, predictable and intentional. These habits alone can improve CLS, optimise CLS score and naturally reduce layout shifts and improve CLS score across the entire experience.

Your Before & After of What a Stable Page Really Looks Like

Before:

You tap a link and wait for the page to settle, but it never happens quickly. The hero image shows up late, the call-to-action button jumps as the font switches, and the navbar drops a few pixels after hydration kicks in. Users won’t analyse the cause. That tiny moment of instability interrupts focus and nudges them closer to bouncing.

After:

The page loads instantly. Every element settles into its spot without hesitation. Images appear inside neatly reserved spaces. Text renders cleanly with zero movement. Dynamic components fade in instead of shoving anything aside. The experience feels premium and fast, even though the design itself hasn’t changed at all.

And this contrast is what a strong CLS strategy actually delivers!

Speed, Stability, Vibes: That’s How We Build the Web

At Echovme, we don’t fix metrics for the sake of dashboards. We value performance so that people can feel the moment a page loads. Speed, stability and visual clarity are not technical add-ons; they are core to how a brand earns trust online. We design layouts that optimise rendering paths, reduce friction and refine loading patterns so every element appears with intention. From improving CLS and LCP to strengthening overall page experience, we build frameworks that work in real-world conditions, not just lab tests.

For us, performance is a craft. When your website feels seamless, your brand feels stronger, and that’s the outcome we deliver every single time.

Finally…

Improving visual stability is a core requirement for search visibility, conversions, and user trust. When you reduce unexpected movements on a page, you make every interaction feel smoother, faster, and more reliable. Whether you’re refining image dimensions, stabilising ads, optimising fonts, or restructuring dynamic elements, every fix contributes to a more predictable browsing experience.

FAQs

1. How to improve cumulative layout shift (CLS) score?

To improve cumulative layout shift, define dimensions for every image, video and ad, preload key fonts, sequence scripts correctly and reserve space for dynamic elements. Reducing late-loading components and preventing unexpected visual jumps ensures better stability. These steps help reduce layout shifts, improve page experience and create a smoother visual flow across devices.

2. What is cumulative layout shift (CLS)?

Cumulative Layout Shift (CLS) measures how often visible elements move unexpectedly as a page loads. These shifts typically occur due to late-loading images, ads, fonts or dynamic components. A low CLS score indicates stable visuals, while a higher score signals disruptive layout movement that affects user experience, readability and overall page trust.

3. How to fix cumulative layout shift in WordPress?

To fix CLS issues in WordPress, set explicit width and height for images, use responsive placeholders, preload fonts, choose lightweight themes, avoid injecting content above the fold and reserve space for ads or dynamic blocks. Optimised caching, CDN delivery and removing render-blocking plugins also help improve page stability and reduce layout shifts.

4. What causes a high CLS score?

A high CLS score usually comes from elements that load late or shift after rendering, like images without set dimensions, auto-resizing ads, delayed fonts, injected banners or scripts that push content downward. Any unexpected movement during loading contributes to cumulative layout shift and disrupts user experience, especially on slower networks or mobile devices.

5. What is the CLS issue more than 0.1 on mobile?

A CLS score above 0.1 on mobile indicates that users are experiencing noticeable layout shifts as the page loads. Since mobile screens have limited space, even small movements feel more disruptive. Scores above this threshold suggest missing dimensions, unstable ads, late-loading fonts or scripts and require optimisation to maintain a stable browsing experience.