PNG to WebP Converter: Convert PNG to WebP Online

Convert PNG to WebP

WebP is the format PNG should have been. It supports lossless compression (like PNG) and lossy compression (like JPEG), with an alpha channel in both modes. The result: files that are significantly smaller than PNG at the same visual quality, with full transparency support.

Drop a PNG file above to convert it to WebP. Adjust the quality slider for lossy output, or select lossless mode to get a smaller-than-PNG file with zero quality loss.

Why WebP Over PNG

Smaller lossless files

WebP’s lossless compression uses several techniques that PNG does not: predictive coding that references neighboring pixels, a backward reference cache, and color space transforms that exploit spatial redundancy. The result is files that are 20-30% smaller than equivalent PNGs.

For a website serving many PNG assets (icons, UI sprites, screenshots), switching to WebP lossless saves bandwidth without any quality compromise. A sprite sheet that was 150 KB as PNG becomes 110 KB as WebP. Multiply that across dozens of assets and page loads, and it adds up.

Lossy compression with transparency

This is where WebP truly differentiates from PNG. PNG is lossless only. If you want a smaller file, your only options are reducing dimensions or color depth. JPEG is lossy but has no transparency.

WebP gives you lossy compression with a full alpha channel. A product image with a transparent background that was 500 KB as PNG can drop to 50-80 KB as lossy WebP at quality 85, with the transparency perfectly preserved and no visible quality difference at normal viewing sizes.

This is transformative for e-commerce, where product images need transparency for compositing over different backgrounds, but also need to be small for fast page loads.

Animation support

WebP also supports animation, serving as an alternative to GIF with better compression and true color depth (24-bit vs GIF’s 8-bit palette). This is outside the scope of PNG to WebP conversion but worth knowing if you work with animated assets.

Browser Support in 2025

WebP has reached effective universality. Every current browser on every current platform supports it:

• Chrome: since version 17 (2012)
• Firefox: since version 65 (2019)
• Safari: since version 14 (2020)
• Edge: since it switched to Chromium (2020)
• iOS Safari: since iOS 14 (2020)
• Android browsers: since Chrome for Android added support in 2014

The remaining 3% without support consists of users on Internet Explorer (end of life) or very old mobile browsers that rarely receive software updates. Unless your analytics show meaningful traffic from these sources, WebP is safe to use as a primary format.

For the rare cases where you need a fallback, the HTML <picture> element lets you serve WebP with a PNG fallback:

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

Most CDNs and image services handle this automatically via content negotiation.

Lossless vs Lossy: Choosing the Right Mode

Use lossless when:

• The PNG contains screenshots, text, UI elements, or diagrams
• Pixel-level accuracy is required (technical documentation, pixel art)
• You want a drop-in PNG replacement with no tradeoffs except smaller files
• The image will be edited further after conversion

Use lossy when:

• The PNG is a photograph or complex illustration
• The image has many colors and gradients
• Maximum file size reduction is the priority
• The image is destined for web delivery at normal viewing sizes

Lossy WebP at quality 80-85 typically produces files 60-80% smaller than the source PNG with no perceptible quality difference in photographs. Lossless WebP saves 20-30% compared to PNG. The choice depends on whether you prioritize size or bit-for-bit accuracy.

File Size Comparison

The lossy column assumes photographic or complex content. For screenshots and graphics with flat colors, lossy WebP at high quality settings still produces good results, but the savings over lossless are smaller because there is less high-frequency detail to discard.

For the complete set of format conversion options, see the Image Converter. To encode images as Base64 data URIs for inline embedding, use the Base64 Encoder.