A new online service that is now at the height of a fuss. enlarge photo online Very effective editor for your photos. Makes quality better.

Thank you, Susan. It was indeed a great tool. 

But I discovered new tool, ImgUpscaler, probably a better option than the one you recommended.
 

Why is that so?

Its FREE.
Its Fast and support bulk processing

The most important thing is the accuracy this tool provides. I mean, it just output like an original image. Kudos to the creators.