I want to convert the images I get online to ahigh resolution so that I can set it as my desktop on my laptop. So how can I convert image to high resolution online?
To convert the images to higher resolution is not likely possible but if you want to change the sharpness of the image it is possible by using any online tool. By using the online tools you can change the sharpness and make the image look crisper but if you add too much of sharpness its image will start looking cranky and unrealistic. So you need to give a correct amount of sharpness and take it to another level. Now even if the resolution is not increased the image will remain crisp on your desktop.  
