How to Optimize Images for Search Engines
Images not only help a webpage look great, they are also an important part of a website’s search rankings. The following will examine some of the most important elements search engines use to determine which images to index.
Numerous specialty search engines, also known as “verticals,” exist within major search engines, such as Google, Yahoo and Bing. A vertical is simply search engine that focuses on a specific type of Web content, such as the items on the Google menu bar (YouTube, Google Shopping, Google Images etc.). Following the best practices will not only increase the likelihood of a webpage being ranked higher for relevant keywords in a general search, but also the image being found through a vertical.
In addition to being found through searches on these verticals, content within these categories can also appear in the general web search results. Therefore, it is important to optimize all forms of online content to be indexed by search engines.
Here are a few ways to improve the likelihood of getting search engines to index an image:
- Descriptive Alt Tags: Search engines are able to see that an image is on a webpage, but it cannot read what the image is without a little help. Alt tags provide search engines with a description of the image, which are used in indexing images in search results.
- Title Tags: Like alt tags, title tags also help search engine bots know what the image displayed is all about. It should be short, catchy and descriptive. In FireFox, Opera, and other browsers, the title tag pops up when a visitor hovers over an image.
- Image File Names: Include keywords that describe the image in its file name. For example, the file name web-design-professional.jpg would be a better name than stockpic18662k334d772.jpg for the image below. Also notice that the name of the file is more than one word, which have been separated or “parsed” with hyphens. Although website copy should be written naturally, image files should exclude non-keywords in the title.
- Image Size: Large photos should be resized to help preserve page speed. The image size should also be included in the html on the page to give search engines details on the size of the photo. (Note that the image size code should not be used to resize the image on the page). Images should be resized prior to being uploaded to the website.
- Add Keyword Rich Captions: Adding keyword-rich captions directly above or beneath an image can also improve its chances of being indexed higher by search engines.
- Anchor Text: Just like using links to a page or article, including good anchor text is important when linking to an image. Using the picture below as an example once again, change generic links, such as “View Photo,” to something like “Website Developer – View Larger” to include keywords in the anchor text.
- File Formats: If you have access to Photoshop or a similar program, take advantage of the “Save for Web” option to optimize a photo. If this is not an option, try to save photos in JPEG format and set to a resolution of 72 pixels per inch. A full discussion of image format & SEO is beyond the scope of this article, website owners may also want to look into Google’s WebP image format.
Image Optimization Helpful Hints
Image Optimization Helpful Hints
In addition to these more technical aspects, some general SEO rules apply to images as well.
- Avoid Keyword Stuffing: Stuffing keywords into any of the areas discussed above will be seen as a “black hat” SEO tactic by search engine and have a negative impact on search rankings. Instead, use keyword-rich text that is written in plain English.
- User Experience: Like all other content on a website, images should be chosen based upon the value it will add to the visitor’s experience. Carefully select pictures or graphics that will both resonate as well as immediately communicate the message of that web page. Put differently, if a picture is worth a thousand words, make sure it reinforces a message consistent with the text on the page.
- Consider Image Quality: Good quality photos make for a better user experience, so avoid using blurry or low resolution photos. However, before you start uploading huge, high resolution images; remember files that are too large will take longer to load, slowing down page speed and diminishing the overall user experience.
- Image Placement: Many visitors will not scroll to the bottom of a page, so it is generally a good idea to position images higher on a page. According to Google’s guidelines, image captions, titles, and other content surrounding an image provides search engines with important information used to understand an image.
To conclude, be mindful of how search engines read and index content and how that relates to search ranking. Following best practices for image optimization and general search engine optimization, your website will see drastic improvements.