Google Images

Google Images is a search service created by Google and introduced in July 2001, 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.

In early 2007 Google implemented an updated user interface for the image search, where information about the image, such as resolution and URL, was hidden until the user moved the mouse over the thumbnail. This was discontinued after a few weeks.

On July 20, 2010, Google updated the user interface again, hiding image details until mouse over, like before. This feature can be disabled by pressing "Ctrl + End" on one's keyboard and clicking "Switch to basic version".

On October 27, 2009, Google Images added a feature to its image search that can be used to find similar images.

In 2001, 250 million images were indexed. In 2005, this grew to 1 billion. By 2010, the index reached 10 billion images. As of July 2010, the service receives over one billion views a day. Google introduced a sort by subject feature for a visual category scheme overview of a search query in May 2011.

In October 2011, Google Images began to allow for reverse image searches directly in the image search-bar (that is, without a third-party add on, such as the one previously available for Mozilla Firefox). This feature allows users to search by dragging and dropping an image into the search-bar, uploading an image, selecting a URL, or 'right-clicking' on an image.