It is so easy to use, you just have to slide a bar back and forth until you find your desired image size. It usually takes less than 60 seconds to upload the image, resize it, and then save to your computer in an image format of your choice. As you are sliding the marker across you can see the details of your image change in the boxes below.
You can also adjust your image, rotate it, change it to sepia, black and white, crop it, and more.