What is een ALT-tag?

An ALT tag is added to a web page to describe elements that may not be visible under certain circumstances. This often involves additional text being added to an image, for example. This alternative text becomes visible as soon as the image cannot be displayed. This way, the text will always be legible, even when crucial parts cannot be displayed properly. An ALT tag has been added to all sites since the arrival of HTML 2. It is not only an aid for the visitor, but it can also have an effect on the SEO-score of a webpage. But what exactly is an ALT tag? How do you add it? And what are the SEO benefits of using this alternative text? 

Definition ALT tag 

A webpage usually contains several types of content. The most important content are the texts and images. After all, these provide the information (or support the information) for the reader. However, if the reader has a visual impairment or if the media cannot be uploaded properly, this may cause them to go to another website. To prevent this, an ALT tag can be added to the web page. This allows an alternative text to be created within the HTML to describe the whole. In this way, the media is not necessary to understand the story. This description is only visible by hovering the mouse over the image. In some cases, the ALT tag can also be played back audibly. This makes it easier to understand for people with visual impairments. 

Importance for SEO 

The ALT tag is not only used to make things easier for the reader. It is also used to improve the SEO value of the web page. By describing the images in words, Google's search algorithm can better read the information and also use this to determine the ranking of the site. The disadvantage of many images is that they cannot be read by the web crawlers. This means that a very important image has little to add to the SEO value of the site. Especially when the subtitle is not descriptive enough either. 

In addition, images do not always work optimally. When they have a very important supporting function for understanding the text, this will also lead to people clicking through to another website. This is also seen by Google. And when this happens too often, it will have consequences for the ranking of the web page. Thanks to an ALT tag, you prevent this and offer the reader a better experience. Even when the content does not cooperate.