There are lots of reasons for using reverse image search – see my earlier post, Here’s why you and your business should use reverse image search – and quite a few ways to do it. The main ones are the TinEye and Google Image Search websites, both of which are free. Depending on your location, needs and personal preferences, you might also want to try Baidu, Yandex, Bing Image Match, Image Raider or some other service.
But if you’re new to reverse image searching, I suggest you start with TinEye and Google. I use both, because they are different enough to complement one another. TinEye has better features. Google Image Search generally has a bigger, fresher database, though it doesn’t find all the images that TinEye knows about.