Alt text: what it is and how to write it


In this guide, you’ll learn about alt text (alt text): what it is, why it’s important for SEO, how to use it correctly, and more!

This is a very practical and accurate guide that contains tips and advice that you can immediately use to improve your website’s SEO and image accessibility.

What is alt text?

Alternate text (or alt text), also known as an alt attribute or alt tag (which isn’t technically correct because it’s not a tag), is simply a piece of text that describes the image in the HTML code.

What are the uses of alt text?

The primary function of alt text was simply to describe an image that could not be loaded.

Many years ago, when the internet was much slower, alt text helped you know the content of an image that was too big to load in your browser.

Today, images rarely fail to load, but if they do, you’ll see alt text instead of an image.

Screenshot by author, August 2022

Now, alt text has also started to play a role for search engine crawlers and screen reader users:

  • Alternative text helps people with disabilities (for example, using screen readers) learn more about the content of the image.
  • Alt text also helps search engine crawlers understand the content and context of the image.

Of course, like any element of SEO, it is often misused and even, in some cases, abused.

Now let’s take a closer look at why alt text is important.

Why alt text is important

The web and websites are a very visual experience. It’s hard to find a website without images and graphics.

This is why alt text is very important.

Alt text helps translate the content of the image into words – thus making the image accessible to a wider audience, including people with disabilities and search engine crawlers who aren’t yet smart enough to fully understand each image, its context and meaning.

Why Alt Text is Important for SEO

Alt text is an important part of on-page SEO optimization.

Proper alt text optimization gives your website a better chance of ranking in Google image search.

Yes, alt text is a ranking factor for Google image search.

Depending on the niche and specificity of your website, Google image search traffic can play a huge role in the overall success of your website.

For example, in the case of e-commerce sites, users very often start their product search with a Google image search instead of typing the product name into the standard Google search.

Google image search results for the phrase Screenshot of the search for [Garmin forerunner]Google, August 2022

Google and other search engines may display fewer product images (or not display them at all) if you don’t take care of optimizing their alt text.

Without good image optimization, you risk losing a lot of traffic and potential customers.

Why alt text is important for accessibility

Visibility in Google image search is very important, but there is an even more important consideration: accessibility.

Fortunately, in recent years there has been a greater emphasis on accessibility (i.e. making the web accessible to everyone, including people with disabilities or/and using screen readers).

Suppose the alt text of your images actually describes their content instead of, say, stuffing keywords. In this case, you are helping people who cannot see this image better understand it and the content of the entire web page.

Let’s say one of your web pages is an SEO audit guide that contains screenshots of various crawler tools.

Wouldn’t it be better to describe the content of each screenshot instead of placing the same “SEO Audit” alt text in each image?

Let’s take a look at some examples.

Alternate Text Examples

Finding plenty of good and bad alt text examples isn’t hard. Let me show you a few, sticking to the example above with an SEO audit guide.

Good examples of alt text

For example, our sample SEO guide contains screenshots of tools such as Google Search Console and Screaming Frog.

Here are some good examples of alt text:


Point: It’s also a good idea to take care of the name of your file. Using descriptive filenames is not a ranking factor, but I recommend it as good SEO practice.

Examples of incorrect and/or spammy alt text

I’ve also seen many examples of alt text misuse, including keyword stuffing or spamming.

Here’s how you can turn the good examples above into bad examples:


As you can see, the examples above don’t really provide any insight into what these images actually show.

You can also find examples and more image referencing advice on Google Search Central.

Common Alt Text Mistakes

Stuffing keywords in alt text isn’t the only mistake you can make.

Here are some examples of common alt text errors:

  • Non-use of alt text or using empty alt text.
  • Use the same alt text for different pictures.
  • Use very general alt text which doesn’t actually describe the image. For example, using the alt text of “dog” on a photo of a dog instead of describing the dog in more detail, what color it is, what it does, what breed it is, etc.
  • Automatic use of file name as alt text – which can lead to very unfriendly alt text, such as “googleseachconsole” or “google-search-console” or “photo2323”, depending on the file name.

Alt text writing tips

And finally, here are the tips on how to write proper alt text so that it actually serves its purpose:

  • Do not include keywords in the alt text. It won’t help your web page ranking for those stuffed keywords.
  • Describe the image in detail, but keep it relatively short. Avoid adding multiple sentences in the alt text.
  • Use your target keywords, but naturally, as part of the image description. If your target keyword doesn’t match the image description, don’t use it.
  • Do not use text on images. All text must be added as HTML code.
  • Do not write “this is an image of”. Google and users know it is an image. Simply describe its contents.
  • Make sure you can view the content of the image just by reading its alt text. This is the best exercise to make sure your alt text is OK.

How to check if a page uses alt text

Now you know all the best practices and common alt text mistakes. But how do you actually check what’s in the alt text of images on a website?

You can parse alt text in the following ways:

Inspecting an element (right click and select Inspect while hovering over an image) is a good way to check if a given image has alt text.

However, if you want to check this in bulk, I recommend one of the two methods below.

Inspect an element to check alt textScreenshot by author, August 2022

Install Chrome Extension Web Developer.

Chrome Web Developer ExtensionScreenshot by author, August 2022

Next, open the page whose images you want to audit.

Click on Web developer and access Pictures > Show Alternate Attributes. This way you can see the alt text content of all images on a given web page.

Chrome web developer with images disabled to check alt textScreenshot by author, August 2022

To check the alt text of images throughout the website, use a crawler like howling frog Where site bulb.

Explore the site, access the image report and review the alt text of all images on the website.

More resources:

Featured Image: Khosro/Shutterstock


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