Image search optimization is a form of search engine optimization (SEO) that focuses on targeting specific keywords for image searches. This strategy helps different web pages place higher on search engine results pages (SERPs) for images, helping to increase page rank for the main site. Many websites will also target keywords through image searches in addition to standard searches to attract new visitors who might click ads, purchase products, or boost revenue in other ways. Websites that use image search optimization will often include relevant image file names, high resolution images, appropriate captions and descriptions, and surrounding text that complements the image.
One of the components of this form of SEO is image naming. Websites interested in moving up in search results will often strategically name their images to match searchable keywords. This often involves removing the letters and numbers commonly assigned to images by cameras or image software and replacing them with relevant words and phrases.
Search engines cannot distinguish individual words if they are placed together with no spaces or dividers. Since spaces cannot exist in online file names, words should be separated by hyphens or underscores to allow for proper SEO. The words chosen should both fit the image and attempt to match targeted keywords that are commonly searched or that apply to the rest of the website. Image quality and resolution is also a consideration, and higher quality images and varied image resolutions gain more clout with search engines.
Descriptions and captions are also helpful in placing an image in the search results. The alt attribute, which displays a description to readers who mouse over the image, should contain the targeted keyword or related keywords. This space is another opportunity to make use of image search optimization, but it should remain coherent, useful to the website visitors, and relevant to the website as a whole. Captions can also provide more information to readers while including relevant keywords.
Another opportunity for image search optimization lies in the text that surrounds the image. A few keywords in the text that match up with the image naming and alt description could help raise an image in the SERPs. As with other forms of SEO, targeted keyword phrases only need to occur a few times in the image name, description, and text. Not only will this reduce the chance that search engines will mark the page as spam due to too many keywords, it will also increase relevance to the readers, increasing the likelihood that they will revisit the page.