WhatTheFont is an online service which lets you detect the font used in a logo or image just by uploading it.It identifes the font type by scanning the image or logo.
It supports most common image formats - GIF,JPEG,TIFF,BMP etc.The maximum image size is around 360 x 275 pixels. The ideal letter height for the best search result is about 100 pixels. Try to get the text horizontal and make sure letters are not touching. WhatTheFont will only recognize uppercase and lowercase letters.