Alt text is used to help computers read images.
But can alt tags affect your organic search rankings?
Read on to learn whether there is any connection between alt text and improved Google rankings.
The Claim: Alt Text is a Ranking Factor
What is alt text?
Alt text is an HTML image attribute. It allows you to create an alternative text version of your image in the event the image is unable to load or there is an accessibility issue.
Because of its importance to Google Image Search, it is considered a ranking factor.
Alt Text as a Ranking Factor: The Evidence
Google emphasizes the importance of alt text in multiple ways.
In Google Search Central’s “Search Engine Optimization Starter Guide,” they state the following about the use of alt tags:
“…optimizing your image filenames and alt text makes it easier for image search projects like Google Images to better understand your images.”
In Google Search Central’s Advanced SEO documentation, you will find a page on image best practices. In a section called about alt text, Google discusses the use of alt text.
“Google uses alt text along with computer vision algorithms and the contents of the page to understand the subject matter of the image. Also, alt text in images is useful as anchor text if you decide to use an image as a link.”
While they don’t specify that alt text will improve your rankings, they do warn webmasters that improper use can harm your website.
“Avoid filling alt attributes with keywords (keyword stuffing) as it results in a negative user experience and may cause your site to be seen as spam.”
They also offer the following examples of good and bad alt text usage.
In 2020, John Mueller, Google Search Advocate, answered a question about the alt text of a quote image during a Google Webmaster Office Hours. In the answer, he talked about how Google uses it:
“For Search, what happens with the alt attribute is we use that to better understand the images themselves, in particular, for Image Search. So if you didn’t care about Image Search, then from a Search point of view, you don’t really need to worry about alt text.
But if you do want these images to be shown in Image Search, which sometimes it makes sense to show fancy quotes in Image Search as well, then using the alt attribute is a good way to tell us this is on that image and we’ll get extra information from around your page with regard to how we can rank that landing page.”
Moz mentions ranking factors in relation to alt text. Instead of saying that the alt text itself is a ranking factor, Moz advises:
“…alt text offers you another opportunity to include your target keyword. With on-page keyword usage still pulling weight as a search engine ranking factor, it’s in your best interest to create alt text that both describes the image and, if possible, includes a keyword or keyword phrase you’re targeting.”
In 2021, during a Twitter discussion about ALT text having a benefit on SEO, Google Developer Martin Splitt said:
“Yep, alt text is important for SEO too!”
Alt Text as a Ranking Factor: Our Verdict
There is no specific mention of alt text as a ranking factor for Google search.
It’s clear that if you want your images to appear in Google image results, then you do need to craft descriptive, non-spammy alt text.
So, based on the comments made by Google representatives, plus all the supporting information we’ve found, we’re calling alt text a confirmed Google ranking factor.
Featured image: Paulo Bobita/SearchEngineJournal