Side-by-Side Comparison

These are images from Google WebP Gallery. PNG8 images are 256-color images with alpha transparency (which is a maximum quality for this type) and they generally have lower quality than WebP versions.

WebP with alpha compression does quite a good job. However, "lossy" PNG compression isn't far behind and it works in all browsers (even IE6) rather than only Google's own.

PNG

WebP-lossy (with alpha)

PNG, optimized

"Yellow Rose" 1

PNG file size: 118.5 KB
WebP-lossy (with alpha) Image
WebP-lossy (with alpha) file size: 23.4 KB
Standard PNG8 Image
Standard PNG8 file size: 29.8 KB
"baby tux for my user page" 2

PNG file size: 40.5 KB
WebP-lossy (with alpha) Image
WebP-lossy (with alpha) file size: 17.3 KB
Standard PNG8 Image
Standard PNG8 file size: 18.5 KB
"PNG transparency demonstration" 3

PNG file size: 215.8 KB
WebP-lossy (with alpha) Image
WebP-lossy (with alpha) file size: 83.2 KB
Standard PNG8 Image
Standard PNG24 file size: 112.6 KB.
Standard PNG8 file size: 46.3 KB
"Gregor Mendel's 189th Birthday" 4

PNG file size: 63.3 KB
WebP-lossy (with alpha) Image
WebP-lossy (with alpha) file size: 24.2 KB
Standard PNG8 Image
Standard PNG8 file size: 15.9 KB
"Transparent compass card for overlays" 5

PNG file size: 127.1 KB
WebP-lossy (with alpha) Image
WebP-lossy (with alpha) file size: 67.7 KB
Standard PNG8 Image
Standard PNG8 file size: 15.8 KB

Credits for the images

The images on this page come from a number of different sources. Credits for the images above are listed here in order.

1 "Free Stock Photo in High Resolution - Yellow Rose 3 - Flowers"
Image Author: Jon Sullivan
This file is in the public domain.
PNG source
2 "baby tux for my user page"
Image Author: Fizyplankton
This file is in the public domain.
PNG source
3 "PNG transparency demonstration"
Image Author: POV-Ray source code
Photo licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
PNG source
4 "Gregor Mendel's 189th Birthday"
Image Author: Google Doodle team
Thanks to the Google Doodle team for this image.
PNG source
5 "Transparent compass card for overlays"
Image Author: Denelson83
This file is licenced under the Creative Commons Attribution-Share Alike 3.0 Unported license.
PNG source

Reproducing the images

ImageAlpha (using new pngquant) + ImageOptim.