What is WebP? A Guide to the Modern Web Image Format

What is WebP?

WebP is a modern image format developed by Google that provides superior compression for images on the web. It was created to replace JPG, PNG, and GIF for web use, offering smaller file sizes without sacrificing visual quality.

The name "WebP" stands for "Web Picture format." Google open-sourced WebP in 2010, and it has since become the recommended image format for web performance.

Why WebP matters for websites

Page loading speed is a critical factor for both user experience and search engine rankings. Images typically account for 50–70% of a web page's total file size. Switching to WebP can dramatically reduce this:

• 25–35% smaller than JPG at equivalent quality
• 26% smaller than PNG while supporting transparency
• Faster page loads — especially important on mobile networks
• Better Core Web Vitals — Google's page experience signals include loading performance
• Lower bandwidth costs — less data transferred per page view

Google explicitly recommends WebP in its web performance documentation and PageSpeed Insights reports.

WebP features

Lossy compression

Like JPG, WebP supports lossy compression for photographs. At the same visual quality, WebP files are significantly smaller.

Lossless compression

Like PNG, WebP supports lossless compression for graphics, screenshots, and images where every pixel matters.

Transparency

WebP supports alpha channel transparency, making it a direct replacement for PNG in many cases. A transparent WebP is typically 26% smaller than the equivalent PNG.

Animation

WebP supports animated images, serving as a modern replacement for GIF. Animated WebP files are significantly smaller than GIF equivalents.

Browser support

As of 2026, WebP is supported by all major browsers:

With Internet Explorer officially retired, WebP is safe for virtually all web audiences. For the rare cases where fallback is needed, serve JPG alongside WebP using the HTML <picture> element.

When to use WebP

Use WebP for:

• Website images (hero banners, blog images, product photos)
• E-commerce product galleries
• Blog post featured images
• Background images in CSS
• App web views and hybrid apps
• Any image served over HTTP/HTTPS

Don't use WebP for:

• Email images (use JPG)
• Social media uploads (use JPG)
• Print materials (use JPG or TIFF)
• Sharing with users who may use desktop apps without WebP support

How to convert images to WebP

Convert PNG to WebP

Best for graphics, screenshots, and images with transparency. → PNG to WebP converter

Convert JPG to WebP

Best for photographs and images already in JPG format. → JPG to WebP converter

Batch conversion workflow

1. Collect all images you want to optimize
2. Upload up to 30 files to the converter
3. Download all WebP files as a ZIP
4. Replace images on your website
5. Update HTML <img> tags or use <picture> elements with WebP source

WebP vs AVIF

AVIF is an even newer format that offers 20–30% better compression than WebP. However:

• WebP has broader tool support and simpler implementation
• AVIF encoding is slower and more CPU-intensive
• WebP is the practical choice for most websites today
• AVIF is worth considering for high-traffic sites where every kilobyte matters

JPGConvert.io also supports AVIF conversion for early adopters.

Implementing WebP on your website

Simple approach

Replace image files directly. If your site uses <img src="photo.jpg">, convert the file to WebP and update the src: <img src="photo.webp">.

Progressive enhancement

Use the HTML <picture> element to serve WebP with JPG fallback:

<picture>
  <source srcset="photo.webp" type="image/webp" />
  <img src="photo.jpg" alt="Description" />
</picture>

Modern browsers load the WebP; older browsers fall back to JPG automatically.

Measuring the impact

After converting images to WebP, check your results:

1. Google PageSpeed Insights — Run before and after conversion
2. Browser DevTools — Network tab shows file sizes per image
3. Core Web Vitals — Monitor LCP (Largest Contentful Paint) improvement
4. Google Search Console — Track page experience signals over time

Most websites see a measurable improvement in page speed scores after converting images to WebP.

Related guides: JPG vs PNG vs WebP · Compress images for websites