How to Improve Core Web Vitals by Converting PNG to WebP (No Plugins Needed)

Google now uses Core Web Vitals as a ranking factor — and slow-loading images are a major reason websites fail.

If your site is struggling with LCP (Largest Contentful Paint) or the “Serve images in next-gen formats” warning, the fix may be easier than you think:

Convert your PNG images to WebP — the lightweight, next-gen image format that drastically improves page performance.

🚨 Why Core Web Vitals Matter (Especially LCP)

Google Core Web Vitals measures real-world user experience. The three main metrics are:

LCP (Largest Contentful Paint) — how fast your biggest visible image or text loads
FID (First Input Delay) — how quickly the page reacts to user input
CLS (Cumulative Layout Shift) — how stable the layout is while loading

Of these, LCP is often caused by large PNG images — especially in banners, hero sections, or product images.

Solution: Switch from PNG to WebP and reduce your LCP time dramatically.

💡 Why WebP Helps You Pass Core Web Vitals

WebP images load faster because they are:

📉 Up to 40% smaller than PNGs
💡 Fully supported on all modern browsers
📱 Optimized for mobile and slow connections
🧠 Compressed efficiently without visual quality loss

Reducing image size is one of the top 3 recommendations for improving LCP scores in Google PageSpeed Insights.

🛠️ How to Convert PNG to WebP for Free (No Plugins or Tools Needed)

Use pngtowebp.org to instantly convert your images to WebP — no logins, no setup, no coding.

Steps:

Go to pngtowebp.org
Upload your PNG image
Click “Convert”
Download the optimized WebP file
Replace your old PNGs with the WebP files on your site

In most cases, just updating a few large PNGs in the hero section or product pages can improve LCP by over 30-50%.

✅ Bonus: Use the <picture> Tag for Backward Compatibility

To ensure your images load in both modern and older browsers, use the <picture> tag with fallback:

<picture>
  <source srcset="image.webp" type="image/webp">
  <img src="image.png" alt="Optimized image">
</picture>

This delivers WebP to most users while still serving PNG to unsupported browsers (very rare).

📈 Real Results: Speed Gains from Switching to WebP

Example: A PNG image at 900KB, converted to WebP becomes ~540KB. If that image is the main banner or hero element, your LCP score instantly improves.

WebP helps you pass:

✅ Google PageSpeed “Serve images in next-gen formats” audit
✅ Largest Contentful Paint (LCP) metric
✅ Cumulative Layout Shift (by reducing lazy load shifts)

🎯 Final Step: Start Optimizing Now

Use pngtowebp.org now to fix your Core Web Vitals scores with faster, cleaner, smaller images.

No plugins. No fees. Just better performance — and better rankings.

pngtowebp.org — Convert PNG to WebP and pass Core Web Vitals with ease.