Is it possible to resize an image online? Without going through an editor on our computer, such as Adobe Photoshop which is very heavy at the end or can only be used on Windows systems.
There are several solutions, some also allows to crop the picture, to add effects.
Example with picresize: http://www.picresize.com/
Even Adobe offers to Internet users a soft version of its software, only the installation of Adobe Flash Player will be required. It is called Adobe Photoshop Express Editor: