The most comprehensive image search on the web.
Google Images is a search service created by Google that allows users to search the Web for image content.
The keywords for the image search are based on the filename of the image, the link text pointing to the image, and text adjacent to the image. When searching for an image, a thumbnail of each matching image is displayed. When the user clicks on a thumbnail, the image is displayed in a box over the website that it came from. The user can then close the box and browse the website, or view the full-sized image.
Google was offering voice and search by image for mobile phone but now Google has introduced voice and search by image for desktop too. Now you can search image with the help of another image.
With new Google search by image you can upload image and Google will identify that image and show you the related results like landmark for a place or related images etc. You can search by uploading or copy paste URL of image. Google Search by Image is rolling out in 40 languages. Google will soon release Chrome and Firefox extensions that enable you to search any image on the web by right-clicking. Google search by image will be fully rolled out in few days.
Comments and Reviews
effectively search image based on URL or image upload
When reverse searching, often refers to useless images, so you have to use TinEye, Bing, Yandex, Baidu and lots more to find it. So far, Bing and Yandex have given more precise answers to unknown images (based on similarity), while TinEye manages to find the exact image (though, at times, the site is already down, you're gonna have to rely on various sites to resurrect it. Talking about archive.org, archive.is, WebCite, Google Cache etc).
In general, I find Google Image Reverse search rather useless. Not to mention, 90% of the times, it filters your search. DuckDuckGo is better.
[Edited by imh1kiko, November 02] Typos.