Fix Unsized Images Causing Layout Shifts

How to optimize stijnvansprang.nl

WordPress SiteScore: 13/100Analyzed February 2026

Fix Unsized Images Causing Layout Shifts

High Impact+35 points estimated

Why It Matters

Unsized images are causing a severe CLS score of 0.479, creating jarring layout shifts as content loads.

How to Fix

Add explicit width and height attributes to your logo image and content images. In WordPress admin, ensure all images have proper dimensions set. For the lazy-loaded images, configure your Smush plugin to include proper aspect ratio placeholders to prevent layout shifts.

0Poor

What This Score Means

A score of 13 falls in the "Poor" range (50-89). While it is better than poor (0-49), you should aim for 90+ to provide an optimal user experience and maximize SEO benefits.

This site is slower than approximately 35% of similar sites. The main issues affecting performance are image optimization, JavaScript execution time, and layout stability.

Addressing these issues could improve your conversion rate by 15-20% and boost your search engine rankings.

Core Web Vitals Analysis

LCP

Largest Contentful Paint

7.5s
Poor

Good: < 2.5s

Measures how long it takes for the main content to appear on screen

INP

Interaction to Next Paint

1197ms
Poor

Good: < 200ms

Measures how quickly the page responds to user interactions

CLS

Cumulative Layout Shift

0.48
Poor

Good: < 0.1

Measures visual stability - how much content shifts during page load

AI Performance Analysis

This WordPress site has severe performance issues with a critically low score of 13/100. The biggest problem is massive layout shifts caused by unsized images, particularly the logo and project photos, which creates a jarring user experience as elements jump around while loading. Combined with an extremely slow 3D model viewer JavaScript library that takes over 3 seconds to execute and blocks the main thread, the site takes 13+ seconds to become interactive. Fixing image dimensions to prevent layout shifts and optimizing or deferring the heavy model-viewer script could dramatically improve the score by 40+ points and provide users with a much smoother, faster experience.

Other Optimization Recommendations

Optimize Model Viewer JavaScript Performance

High Impact+25 points estimated

Why It Matters:

The 245KB model-viewer.min.js library is blocking the main thread for 3+ seconds and causing 90KB of unused JavaScript.

How to Fix:

Lazy load the 3D model viewer only when needed using intersection observer. Consider switching to a lighter 3D library or compress the existing GLB model file. Move the model-viewer script to load after critical content renders.

Implement Font Display Optimization

Medium Impact+10 points estimated

Why It Matters:

Custom fonts are causing 70ms delays and invisible text during font loading, impacting FCP by 50ms.

How to Fix:

Add 'font-display: swap' to your CSS for Ysabeau Office and other custom fonts in your WordPress theme. Use font metric overrides in your CSS to minimize layout shifts. Consider preloading critical fonts in your theme's functions.php with wp_enqueue_style and preload link tags.

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Keep Your Site Fast After Optimization

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