Best websites to reduce image size without degrading quality

Webresizer.com: excellent site to compress images without losing quality. Main advantage of using webresizer is that you can compress GIF, JPG, PNG images. it uses lossy algorithms to reduce your picture size.

Website: http://webresizer.com/resizer/

Here is an example of output from webresizer. left one is reduced image and right is original image.

webresizer.com