An image can be reduced in size. It is not advisable to increase image size as this may result in a quality reduction.
The finished size of your image will be determined by the intended position on your Web page. View the Image size page for information on appropriate image dimension and related file size.
To resize an image:

Note: This only affects your screen view of the image, not the image itself. It is better to view the actual size of an image while you are editing, so that you don’t get a false impression of the image size.
The following window will open.

Note: You will only need to change the height or width because changing one of these parameters will automatically change the other. The original proportion of the image will be retained.
Note: You will only need to change the height or width percentage because changing one of these parameters will automatically change the other. The original proportion of the image will be retained.