You might be wondering why you would want to do a reverse image search.
You might be wanting to check if anyone is using photos off your website, or who might be using your own mug shot displayed in business websites to impersonate you. You can keep tabs on your own images with reverse searching.
You may have an image you would like a better resolution of or to locate the original creator of the image. You can also use the search to carry out detective work.
Recently I was looking at a very unusually well priced campervan advertised on a forum at a popular Australian camping website. The owner claimed the low price was only due to the family wanting a deposit for a home and needed an urgent sale. It was all very convincing until I downloaded the image and carried out reverse search to discover the original owner had shown it for sale prior at a much greater price. As it turned out the ad was a scam and the ad was gone by the end of day.
You do not need any keywords or any other query to carry out the search, only the image.
There are quite a few image search websites, including google image search, but 2 of my preferred sites are: