Is Your Website’s Layout Shifting? Here’s Why You MUST Fix It!

Have you ever tried to click a button, only for the page to suddenly shift, causing you to tap something completely different? That’s Cumulative Layout Shift (CLS), and it’s wrecking your user experience!

What is CLS?

CLS is a Core Web Vitals metric that measures unexpected layout movement during loading. A high CLS score means a frustrating experience for users—and Google penalizes it in search rankings.

Example:

You’re about to click “Add to Cart”, but—oops! An ad loads at the last second, shifting everything, and now you’ve clicked a random banner instead. 😡

What Causes CLS?

• Images without width & height: If you don’t define dimensions, the browser doesn’t reserve space, causing shifts when images load.
•  Late-loading ads, banners, or popups: Third-party content injected dynamically after page load pushes elements downward.
• Web fonts causing FOUT/FOIT: Fallback fonts differ in size, so when the actual font loads, the text reflows, shifting content.
• Embedded iframes & videos without reserved space: YouTube videos and widgets expand unexpectedly, moving elements below them.

How to Fix CLS Like a Pro?

Set Image Dimensions Properly

<img src=”product.jpg” width=”800″ height=”600″ alt=”Product Image”>

img { aspect-ratio: 4 / 3; }

Reserve Space for Dynamic Elements

.ad-slot { min-height: 250px; }

Preload Fonts to Avoid Reflow

<link rel=”preload” href=”fonts/your-font.woff2″ as=”font” type=”font/woff2″ crossorigin=”anonymous”>

Use font-display: swap;

@font-face {
font-family: ‘CustomFont’;
src: url(‘custom-font.woff2’) format(‘woff2’);
font-display: swap;
}

Fix CLS in Shopify & WordPress

<img src=”{{ product.image | img_url: ‘600x’ }}” width=”600″ height=”400″>

add_filter( ‘wp_lazy_loading_enabled’, ‘__return_false’ );