Infinite Path

Last month, an interview with Peter Linsley, a Google employee, reminded us at Infinite Path about the importance of keeping SEO best practice in mind when it comes to images, particularly alt text, on a webpage.

The interview is really interesting but goes into a lot of detail about this element of SEO. So, we’ve managed to whittle down the basics to provide you with the need-to-know facts about this particular subject:

Why you need to focus upon optimising your images for search

The answer to this is very simple. When we focus upon link building as part of an SEO campaign, it’s done primarily with the intention of building importance. In effect, a link into a particular site represents, in the eyes of the search engine at least, a vote for that site.

Each link sends a clear signal to the search engines that the content on the page being linked to provides useful information for the user. This in turn increases the chances of that website ranking highly for a particular keyword phrase.

The same can be said with regards to content on a particular page. Keyword density, choice of anchor text, and several other content features combine to send a search engine a signal related to relevancy. If the content appears to be mashed together in an irrelevant manner, it is unlikely to be deemed worthy of ranking highly for a particular phrase.

With images, however, importance is not as easy to gage (since, as a general rule, people don’t link to images in the same way they link to content). The search engines therefore need to build confidence in the image through different means. Relevancy is still an important factor to consider in this respect and it is for this reason that images must be optimised for search.

Using alt text

To send search engines the correct signals and attempt to build this confidence, it’s important to use the alt text attribute effectively. This text can be entered into the image source tag and should be used to describe what is in the image. This will send an initial signal to the search engine concerning the content of the image and will start to build confidence that it is related to a specific topic of interest.

Take care to repeat the content from the alt text in other areas of the webpage, preferably in close proximity to the image. For example, provide a relevant title for the image which contains the same keywords as the alt text. This will send a signal to the search engine that the image is about a specific topic and, even better, a topic which is obviously relevant to the wider context of the webpage as a whole.

Why alt text is important from a non-SEO point of view

As with most elements of SEO, the alt text is also important from the point of view of the user. The general rule with any element of SEO is to use common sense and think about matters from the point of view of a website visitor. If any changes you make are initiated to make life easier for the user, the chances are that your site will be improved from an SEO point of view at the same time.

For instance, if you write concise, focused content which constantly reminds the reader of the main theme of the text by using careful keywords, users and search engines will benefit.

With images, the same rule applies. For instance, there are times when an image will take some time to load, leaving the alt text visible. If the alt text is stuffed with keywords or filled with unrelated content, the user will take no value from the experience. Likewise, the search engines will find no use for it. From the user’s point of view, it’s far better to read a concise, accurate description of the image.

Alt text is also useful for individuals using a screen reader or those using a text-only browser.

Rules of image optimisation

• Try to keep the content of the alt text concise and to the point. There are no official hard and fast rules concerning length but if you keep it short, the search engines will be more likely to understand the importance of these words and tie them together with other mentions elsewhere on the page
• Keep it relevant to the content
• Think about the keywords you want to rank for and use these if possible