SEO Best Practices for Alt Text

by Apr 12, 2022Blog

Alt-text is shorthand for Alternative Text for Images. It describes what is in an image for people who are accessing a web page with a screen reader. This is used for people with visual impairments and helps to read computer documents aloud so the person can listen to what is written.

In a recent office hours video, Google’s John Mueller discussed best practices for alt text for SEO.

16 Word Alt Text Limit

There was an SEO test that used non-existent words and discovered that Google could not find images by using more than 16 words to search for them. This brought about the popular idea that there was a maximum of 16 words in an Image Alt Text.

Mueller dispels this myth, “We don’t have any guidelines with regards to how long your alt text can be. So from a Google Search point of view, you can put a lot of things in the alt text for an image, if that’s relevant for that particular image.” The SEO test was flawed since using non-existent words to test tends to result in flawed search results. Google is designed to rank actual words, not gibberish.

How Does Google Use Alt Text?

Mueller explained how Google uses Alt Text and how it affects SEO, “When it comes to the alt text, we primarily use that to better understand the image. So if someone is searching in Google Images for something that kind of matches the alt text, then we can use that to understand that your image is relevant for that alt text on that specific page.

Alt Text helps Google Images better understand the image and helps improve the search results’ relevance.

What Words to Use in Alt Text?

Choosing the right words for Alt Text can affect your SEO, so choosing the right words can have an advantage.

Mueller describes, “When it comes to Google images, you don’t necessarily need to describe exactly what is in the image. But rather, kind of like what this image means for your particular page. So if you have a picture of a beach, you could use an alt text and say, Oh, this is a beach. But you could also say, this is the beach in front of our hotel, or this is the beach that we took a photo of when we were doing a chemical cleanup.

And kind of those intents are very different, and people would be searching in different ways in Google Images to find more information there. And giving that extra context always makes sense.”

Mueller encourages publishers to use words that provide context to the image so that using a screen reader, the audience understands how the image fits into the content of the web page. When deciding what to write for Alt Text, it’s important to think about how someone with a visual impairment would best understand the image.


Alt Text is an important tool for your images to come upon a Google Search. After all, more than 30% of Google’s SERP are images. You could be missing out on an important source of organic traffic if you are not using Alt Text. Need help with figuring out how to use Alt Text. Book a discovery call with us today to learn more.