Alt Text a Factor for Image Search Only, Google Confirms
John Mueller has attempted to quell any remaining confusion regarding how Google factors alt text into its SERP ranking decisions. Specifically, Mr Mueller stated that alt text should be used purely with accessibility in mind, with image search SEO as a secondary point of importance.
Perhaps more significantly, he confirmed that alt text does not hold any specific value when it comes to SERP rankings in standard textual web search.
During the Google Search Central SEO office-hours hangout recorded on March 18, Mr Mueller was quizzed on various aspects of alt text and its potential SEO benefits.
One question pertained to the use of decorative images, and whether it is worth adding alt text to them.
To which, he issued the following response:
“I think it’s totally up to you. So I can’t speak for the accessibility point of view, so that’s the one angle that is there. But from an SEO point of view the alt text really helps us to understand the image better for image search. And if you don’t care about this image for image search, then that’s fine do whatever you want with it.”
“That’s something for decorative images, sometimes you just don’t care. For things like stock photos where you know that the same image is on lots of other sites, you don’t care about image search for that. Do whatever you want to do there. I would focus more on the accessibility aspect there rather than the pure SEO aspect.
“It’s not the case that we would say a textual webpage has more value because it has images. It’s really just we see the alt text and we apply that to the image, and if someone searches for the image we can use that to better understand the image. It’s not that the webpage in the text web search would rank better because it has an image.”
He went on to emphasise the important role alt text plays from an accessibility perspective, which is useful for people using screen readers:
“From a more general point of view, the alt text is meant as a replacement or description of the image, and that’s something that is particularly useful for people who can’t look at individual images, who use things like screen readers, but it also helps search engines to understand what this image is about.”
“If you already have the same description for a product around the image, for search engines we kind of have what we need, but for people with screen readers maybe it still makes sense to have some kind of alt text for that specific image.”
Mr Mueller concluded by issuing a warning against the use of generic text, such as the frequent repetition of product names:
“In a case like this I would avoid the situation where you’re just repeating the same thing over and over. So avoid having like the title of a product be used as an alt text for the image, but rather describe the image in a slightly different way. So that’s kind of the recommendation I would have there.”
I wouldn’t just blindly copy and paste the same text that you already have on a page as an alt text for an image because that doesn’t really help search engines and it doesn’t really help people who rely on screen readers.”