Alt Text for Images: What Is It and Why Does It Matter?

By Sarah Lennon  – 7 minute read

Alt text is one of those small details on a website that is easy to overlook. It takes seconds to add, but it can make an image more useful to search engines, screen readers and the people using your website. It’s also something that is frequently misunderstood.

Alt text — short for alternative text — is a written description associated with an image on a web page. Its primary purpose is accessibility: if someone is using a screen reader and cannot see the image, the alt text helps communicate what the image contains or why it is there. It can also help search engines understand the content and context of an image.

What Does Alt Text Actually Do?

When you add an image to a website, the image itself and its alt text are two different things. In HTML, it looks something like this:

<img src="denver-web-design.jpg" alt="Website design displayed on a desktop computer">

The important part is:

alt="Website design displayed on a desktop computer"

That description gives information about the image when it cannot be seen or interpreted visually. For someone using a screen reader, good alt text can make the difference between understanding what an image contributes to a page and simply knowing that an unexplained image exists. For search engines, it provides another piece of information about the image and the page surrounding it.

Does Alt Text Help SEO?

Yes, but that shouldn’t be the only reason you use it. Search engines have become dramatically better at understanding images. Google can recognise objects, faces, text and many other visual elements without relying entirely on a written description. But context still matters.

An image of a modern building could be illustrating architecture, commercial construction, a web design portfolio, a real estate listing or an article about Denver. The image alone doesn’t necessarily explain why it appears on that particular page. Good alt text, combined with the surrounding page content, helps provide that context. It can also help images appear appropriately in image search and contributes to a well-structured, accessible website.

What Makes Good Alt Text?

The best alt text is usually simple and descriptive. Imagine you had to explain the useful part of the image to someone who couldn’t see it. What would you tell them? For example:

Not very useful:
alt="image"

Trying far too hard for SEO:
alt="Denver web design company SEO website designer Colorado best web design"

Much better:
alt="Custom real estate website displayed on a laptop"

The goal isn’t to cram keywords into the description. It’s to describe the image naturally and in the context in which it is being used. If a relevant search term belongs naturally in that description, that’s fine. If it doesn’t, don’t force it.

Not Every Image Needs a Description

This is another important distinction. Some images are purely decorative. They might be background shapes, textures, separators or other visual elements that don’t communicate useful information. In those cases, the correct approach may be an empty alt attribute (alt=""), which tells a screen reader that the image can safely be ignored. That is better than forcing a meaningless description onto every image on a website. Alt text should be useful, not simply present for the sake of ticking an SEO box.

How to Add Alt Text in WordPress

Fortunately, WordPress makes this extremely easy. When you upload or select an image in the WordPress Media Library, you’ll see an Alternative Text field. Add a short, useful description of the image there. You don’t need to write HTML or add any special code yourself. The short screen recording below shows exactly where to find it and how to add alt text to an image in the WordPress Media Library.

Alt Text, Accessibility and Modern Websites

Alt text is a good example of something that benefits both people and technology. It helps people using assistive technology understand visual content. It gives search engines additional context. And it encourages website owners to think about whether the images they’re using actually contribute something meaningful to the page.

AI and image recognition will undoubtedly continue getting better at interpreting visual content, but that doesn’t remove the need for good website structure or thoughtful accessibility. The technology may be able to recognise what is in an image. The website still needs to communicate why that image matters in context. And for something that takes only a few seconds to add in WordPress, good alt text remains well worth doing.