Alt Tags for Images Bring Useful SEO Benefits

Image courtesy of Twobee / FreeDigitalPhotos.net

Alt tags for images are important in some ways and unimportant in others.

Content management systems offer and encourage the use of alt tags. For example, WordPress has an alt tag box with every image. But the publisher has the option of using it or not using it.

In brief, publishers who use the box are taking advantage of an opportunity for search engine optimization, both for the article and the image.

The opportunity for the article lies with the ability of the alt tag to signal and reinforce the article’s main keyword phrase with search engines. It’s also a chance to use keyword synonyms.

It’s an opportunity for the image because search engines index images. Image searchers may click on the image and reach the article containing it.

Publishers use alt tags in the code that displays images on their websites.  An example looks like this:

<img src=”https://www.sitename.com” width=”400″ height=”200″ alt=”alt tag name” />.

The name “alt tags” means a tag that provides alternative text. The alternative text served two early purposes:

1. To help visually impaired users who use screen readers to understand the content of the image.
2. To display in place of an image if the image file can’t load.

The second purpose in particular is less useful these days. Early web users had to deal with slow modem speeds. They often had good reason to turn off images altogether. Widespread broadband access has made slow speeds much less of a problem.

Alt tags serve a third purpose that has grown in importance in recent years: search engine optimization.

2 SEO Benefits for Alt Tags

Alt tags have two benefits with search engine optimization in their image databases and especially their much more important text databases. Arguably, the benefits are modest at best. But they are still worth pursuing for any website publisher looking for an edge with search engines.

The first benefit is a signal to search engines about the content of the image, whether it’s a photo or graphic.

If the photo is about a cruise ship, and the alt tag is “cruise ship”, search engines logically index the photo somewhere in their image databases and show it to visitors who search on “cruise ship”. If the visitor clicks on the photo to see the original on the source website, that site gets a visitor.

After tagging thousands of images over decades, I have found that this benefit is modest. People who search image databases are looking for ideas to inspire their own image creation, for images they can steal or images they can legally obtain via licenses or public domain. They rarely click on the image link to go to the source website, although every click is worthwhile.

SEO ranking benefit in text databases

The somewhat better benefit for search engine optimization is the signal the alt tag sends about the content of the page to the text database.

An article about cruise ships will likely have that keyphrase and synonyms in the title, headline and body text. An alt tag — along with the image caption — adds another opportunity for a keyphrase or synonym.

So alt tags for search engine optimization are useful to a point. But publishers shouldn’t throw too much effort into perfecting them for SEO because the article keywords carry more weight.

Think of them as having a proper place in an SEO priority list after keywords and synonyms in:

• Titles
• Article bodies
• Summaries
• Meta descriptions
• Image file names
• Image captions

Fortunately, they take only a moment to add during an article production process. Taking one more moment to do it right just might give that article an extra boost in search engines.