What is alt text and why is it important for SEO?

Haley Carroll

  | Published on  

September 29, 2023

If you’ve added quality, relevant images to bolster your blog post, good on you. Photos will help break up the text and make for a more attractive piece, as well as help your readers visualize the information. However, once you add the image into your text, you aren’t quite done yet. 

If you want to get the most benefits from your images, you need to understand the importance of alt text.

There are many technical aspects to SEO, but today we’ll be taking a deep look into alternative text SEO. In this article we will explain what alt text SEO is, why it’s important, how to add alt text to an image, and round it off with a few alt text for images examples. 

Though technical SEO may seem daunting at first, alt text is something that anyone can do for their website, and it can have big payoffs for a relatively small amount of effort. So, let’s get into it. 

What is alt text?

For any images you have on your webpage, you have the opportunity to add alt text to them. 

Alternative text (alt text for short) is a piece of text within the HTML code of an image, whose purpose is to quickly describe the contents (and sometimes the function) of the image on the page. These descriptions are meant to be quite short, usually falling around 100 characters in length. 

Since alt text is hidden within the HTML encoding of an image, you may be wondering what it’s used for.

It turns out, alt text serves a variety of functions, and they're all super important for your SEO efforts!

Alt text is used by screen readers for the visually impaired 

Here's a newsflash - your website is public and anyone can access it. The internet is becoming a necessity in today's world, and with that accessibility becomes a necessity too.

For visually impaired web users, screen readers are used in order to understand the content on their screen, a screen reader simply reads out the page content from top to bottom allowing the user to listen.

When an image has alt text, screen readers will read the alt text out loud in place of the image. This is one of the cornerstones of web accessibility. Users that are unable to see the images, whether they are visually impaired or unable to load the image on their computer/device, will still be able to understand the image’s meaning and purpose. 

Alt text helps a variety of users access more aspects of the webpage, and not just the written copy. This helps your website stay accessible and inclusive to all people browsing the web.

Alt text is used by web crawlers to understand your images

Additionally, including alternative text for your images helps search engines understand and contextualize them. One of the main goals of any SEO tactic is to help search engines understand your content better, and alt text does this specifically for images. 

Googlebot is getting pretty advanced when it comes to image recognition, but alt text helps a lot in understanding the image as it relates to your page - the more you help out search engine crawlers, the more they will help you out in return.

Now we know what alt text does, but is it actually important for SEO? The answer is yes, and read on to find out why.

Why is alt text important for SEO?

First, and as we already stated, alt text will improve the accessibility of your webpage a great deal. The importance of web accessibility cannot be ignored, as all users should be able to appreciate your content equally. Your site should be friendly to all kinds of user traffic. 

Moving past that, we all know that search engine technology has become highly advanced in recent years. This includes image recognition technology, however that doesn’t mean it works perfectly. 

Search engines don’t have eyes like humans do. They do their best to analyze and understand an image, but there is definitely room for error. Search engines may miss key details about an image that humans would be able to distinguish, such as the identity of a person in a photo or other contextual significance within the image.

That’s where alt text comes in. With a specific, descriptive text blurb written by the author, the meaning of the image can be preserved and communicated smoothly to the search engine. Alt text helps the search engine index the image with accuracy and precision, instead of placing the image in a broad category of images that the search engine considers similar (even though the meaning of the images may be different). 

Failing to include alt text for an image will leave an image’s indexing by search engines up to chance. The search engine may correctly identify what the image is, or it may not. Including alt text for an image eliminates that uncertainty and provides the search engine with even more information about the image. 

Therefore, including alt text is guaranteed to help improve not only user experience, but search engine image comprehension as well. So how does one go about writing quality alternative text blurbs for their images?

Alt text best practices

Here is a list of the most important tips to keep in mind while writing your alternative text.

  • Be descriptive and specific. Identify the subject of the image and relevant adjectives to describe it. Include information about the environment of the image, if that’s relevant too. Remember, alt text is meant to help those who can’t see the image to understand what it’s showing, and why.
  • Use keywords (without keyword stuffing). The alternative text code is a great place to include a relevant keyword or two, but you don’t want to cram too many into the same blurb. This would sound choppy for the screen reader to read aloud, and keyword stuffing has detrimental effects that you can read about here
  • Keep it brief. Try to pack as much relevant information in as few words as possible in order to be the most effective with your alt tags. Many screen readers won’t read past 125 characters, so keep this limitation in mind. 
  • Include the purpose. Don’t forget to include the function of the image. For example, if an image of a bouquet leads to a page of your flower shop’s offerings of bouquets to purchase, your alt text should include “button to view bouquets available to buy.”
  • Cut out unnecessary information. You don’t need to include “image of” or “picture of” in your alt text, because this is already implied. Both search engines and screen readers know that alt text represents an image.

Now, let’s get into some examples of alternative text that follow these rules, as well as examples of alt text that could be improved. 

Alt text for images examples

Good alt text: golden retriever getting washed in bathtub

Bad alt text: dog in bath

Good alt text: fashionable young woman sitting at outdoor cafe reading Vogue magazine and drinking coffee

Bad alt text: woman drinking coffee

Good alt text: cropped female hands knitting with beige yarn 

Bad alt text: personknitting


So now you’ve seen what some examples of good and bad alt text are. Following our best practices, you’ll be able to come up with some great alt text for your images on your own. 

Alt text lies within the coding of your webpage, and allows search engines and screen readers to identify what the images on your page are. Adding alt text will only help your ranking on the SERP, especially for searches that are most relevant to your business. 

So the next time you add a helpful image to your blog post, be sure to add alternative text to it.

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