In niche market sectors, alt text is a fantastic opportunity to highlight what makes an image possibly unique on the entire web.
Search Engine Journal has reported on a really interesting answer from Google about the relevance of ‘alt text’ on images in the age of machine vision.
As a reminder, ‘alt text’ is the descriptive text that we can (and should) give for images on our websites, which doesn’t appear on the page but can be read by screen readers for the visually impaired …and of course by search engines. W3C, the HTML standards making body, has a great explanation of ‘alt text’: “Imagine that you’re reading the web page aloud over the phone to someone who needs to understand the page. This should help you decide what (if any) information or function the images have.”
Search engines were traditionally unable to identify what was in an image, which is why ‘alt text’ was a big help to them (and therefore useful for SEO), but increasingly that issue is being overcome. So is ‘alt text’ still of interest in SEO terms, particularly for appearing in Google Image Search?
Providing insight
Google says that using AI vision to understand the image doesn’t provide insight into what that image means in the context of the web page. Its advisor said: “For image search, (it’s) the context that comes from the page-plus-image combination that matters.
“A photo of a beach might be a relaxing poster, it might be the beach from a hotel, it could be the site of a chemical spill. Just knowing that the image is of a beach doesn’t really give sufficient background information to be able to show it in image search appropriately. A lot of it does come from the page, and the alt-text is unique in that it’s what directly connects the image to the page with context.
“Unless your site is a photo agency, traffic for ‘photo of a beach’ isn’t going to be that useful – but for a hotel, having ‘hotel with beach in X’ can be relevant. Again, a lot of that can come from the rest of the page, but the alt attribute value is a unique opportunity to give context.”
So ‘alt text’ is important for SEO because it shows how the image is directly related to the content of the web page. It also needs to be human-written, because any automated system for identifying what’s in an image is not going to understand the context, at least not yet. For those of us operating in niche market sectors, it’s a fantastic opportunity to highlight what makes an image possibly unique on the entire web.