Google’s use of alt text as a ranking factor is limited to image search. It does not add value for regular web search.
This is explained by John Mueller, Google Search Advocate, during the Hangout during Google Search Central SEO office hours recorded on March 18.
Mueller answers several questions related to alt text, leading to a number of takeaways about its impact on SEO.
Adding alt attributes to images is recommended from an accessibility perspective, as it is useful for visitors who rely on screen readers.
From an SEO perspective, alt text is recommended when your goal is to have image ranking in image search.
As Mueller explains, alt text does not add value to a page when it comes to ranking in web search.
Alt text is for image search
In the title question for this article, Mueller is asked if alt text should be used for decorative images.
It’s a judgment call, Mueller said.
From an SEO perspective, the decision to use alt text depends on whether you care about which images show up in image search.
Google doesn’t consider a page more valuable for web search because it contains images with alt text.
When it comes to using alt text in general, Mueller recommends focusing on the accessibility aspect rather than the SEO aspect.
“I think it’s up to you. So I can’t speak from an accessibility perspective, so that’s the only angle there is. But from an SEO perspective, alt text really helps us understand the image better for image search. And if you don’t care about that image for image search, then it’s fine to do whatever you want with it.
It’s something for decorative images, sometimes we don’t care. For things like stock photos where you know the same image is on many other sites, you don’t bother searching for images for that. Do what you want to do there. I would focus more on the accessibility aspect rather than the pure SEO aspect.
We wouldn’t say that a text-based web page is more valuable because it contains images. It’s really just that we see the alt text and apply it 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 textual web search would rank higher because it has an image.
Hear Mueller’s full response in the video below. Keep reading the following sections for more information on alt text.
The SEO impact of alt text
In another question about alt text, Mueller is asked if it’s still worth using alt text when the image itself contains text.
Mueller recommends avoiding using text in images altogether, but says yes — alt text could still help in this case.
“I think ideally if you have text and images, it probably makes sense to have the text right on the page itself. There are many ways to display text creatively on a website these days, so I wouldn’t necessarily try to use text in images and then use alt text as a way to help to that. I think alt text is a great way to help with this, but ideally it’s best to avoid having text in images.
The question goes on to ask if alt text would be useful when there is text on the page describing what is in the image.
In this case, from an SEO point of view, the text of the page would be sufficient for search engines.
However, it would still make sense to use alt text for people who use screen readers.
“From a more general perspective, alt text is intended as a replacement or description for the image, and it’s something that’s especially useful for people who can’t look at individual images, who use things like screen readers, but it also helps search engines understand what that 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 it might still be good to have some sort of alt text for that specific image.
Alt text must be descriptive
Mueller emphasizes the importance of using description alternative text.
The text should describe what’s in the image for people who can’t see it.
Avoid using generic text, such as repeating product names over and over.
“In a case like this, I would avoid the situation where you just repeat the same thing over and over again. So avoid a product title being used as alt text for the image, but instead describe the image in a slightly different way. So that’s the kind of recommendation I would get there.
I wouldn’t just blindly copy and paste the same text you already have on a page as 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.
Listen to Mueller’s full response in the video below:
Featured image: Screenshot from YouTube.com/GoogleSearchCentral, March 2022.