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Optimization6 min read
Why WebP Beats PNG for Website Speed & SEO
Compare image formats — WebP vs PNG vs JPEG — and learn why converting to WebP boosts page load times, improves Core Web Vitals, and helps your Google rankings.
Compare image formats — WebP vs PNG vs JPEG — and learn why converting to WebP boosts page load times, improves Core Web Vitals, and helps your Google rankings.
Images make up roughly 50–70% of a typical webpage's total weight. Choosing the right format can mean the difference between a blazing-fast site and one that hemorrhages visitors—and rankings.
PNG is a lossless format designed for images with sharp transitions, text overlays, and transparency. While it delivers excellent quality, it comes at a steep cost: file sizes are often 3–5× larger than equivalent WebP images.
Large PNG files create three major problems:
WebP, developed by Google, supports both lossy and lossless compression with full transparency support. The results speak for themselves:
| Format | File Size (typical) | Quality | Transparency |
|--------|-------------------|---------|-------------|
| PNG-24 | 500 KB | Lossless | Yes |
| WebP Lossless | 220 KB | Lossless | Yes |
| WebP Lossy (Q80) | 80 KB | Visually lossless | Yes |
That's a 60–80% reduction in file size with no visible quality difference.
Switching your image pipeline to WebP doesn't have to be complicated. You can start by converting your existing PNG assets using free browser-based tools.
For example, converting your legacy images using a [PNG to WebP converter](/tools/png-to-webp) yields better results than keeping them in their original format. If you have JPEG photographs on your site, you can easily switch formats with an online [JPG to WebP utility](/tools/jpg-to-webp) to achieve similar savings.
Once you've converted your images, follow these best practices:
1. Serve WebP with fallback — Use <picture> elements so browsers that don't support WebP get PNG or JPEG
2. Lazy-load below-the-fold images — Use loading="lazy" to defer offscreen images
3. Set explicit dimensions — Prevent Cumulative Layout Shift (CLS) by adding width and height
<picture>
<source srcset="photo.webp" type="image/webp" />
<img src="photo.png" alt="Description" width="800" height="600" loading="lazy" />
</picture>Google has confirmed that page speed is a ranking factor, and Core Web Vitals (LCP, FID, CLS) directly influence your search visibility. Since images are the #1 contributor to LCP, optimizing your image delivery with WebP is one of the highest-ROI improvements you can make.
Real-world results from sites that migrated to WebP:
PNG served us well, but WebP is the present and future of web images. By converting your image library to WebP, you'll deliver a faster, leaner experience to your visitors while signalling to Google that your site deserves a top ranking. Start with a [PNG to WebP converter](/tools/png-to-webp) or [JPG to WebP utility](/tools/jpg-to-webp) today—your page speed score will thank you.