Image SEO: How to Write Powerful Alt Image Tags

Google Images hold over 20% of the search engine market share. That’s more than all of the other search engines competing with Google put together.

Source: Sparktoro Google CTR in 2018: Paid, Organic, & No-Click Searches by Rand Fishkin

As you can see above, the potential for image SEO is huge. If you have images on your site that are worth the user’s attention, you should seize the opportunity.

How to Succeed with Google Images?

You can begin by optimizing a bunch of image SEO-ranking factors such as:

• Alt image text of an image
• Off-page ranking factors
• Title of the page
• Surrounding text of an image
• The uniqueness of an image
• Title HTML attribute
• Filename
• Image dimensions

In this article, I will show you how to optimize the image alt attribute.

5 Benefits of Using Alt Image Text

Alt image text has benefits not only in SEO but also for web accessibility and usability.

1) Alt Image Text is an Important Ranking Factor

Search engines can’t read images, but they can read the alt text, which helps them understand the meaning of the image. Get more traffic to your site by having your images appear in searches.

2) Improve Image Click-through Rate (CTR)

Keywords in the alt attribute can help to improve user’s CTR from search results. It’s visible in a description of the image result, as in this search result:

3) Alt Text as Anchor Text

If an image contains a hyperlink, the alt text represents the anchor text.

4) Web Accessibility

Properly chosen image alt tags are very important in web accessibility. They are used by visually impaired people to understand the context of images.

5) Alt Text Displayed When Images Aren’t Loaded

Not all internet users allow images to be displayed. This is typically due to having internet access with limited data bandwidth. When no image is loaded, the alt image text is visible as seen in the screen capture below:

How to Write SEO-Friendly Alt Text for Your Images: the Basics

Every image should have defined an alt text. Don’t forget about it.

In some cases though, you can leave it empty (alt=””). For example, this works if you use the image to create bullets in a list or as some decoration.

You should also avoid generic alt texts like “picture,” “image,” 123.jpg, etc.

So, what words should you use? Try to imagine that you’re calling your friend. You have to describe him in your image in up to 10 words. What would you say? The answer will be your alt text. Try to be descriptive, but not too much.

To create a new alt text is not so difficult, right? But have you added alt texts to every image on your site in the past? Let’s look at how to find out.

How to Check Your Existing Images for Alt Text

A Fast Check of One Particular Image

Visit one of your web pages in a browser (I used Chrome), open the right-click menu and click on “Inspect.” Then, you will see source code, including alt text:

Inspect All Images on One Web Page

You can quickly check every alt with the Spotibo analyzer. Enter the inspected URL. It will automatically highlight empty and poorly used alt image tags containing filenames or generic tags such as “picture.”

Inspect All Images on a Website

If you want to be really efficient with the image SEO, you should optimize every image on your site. In the previous crawl, using Spotibo, you can see not only one page but an entire website.

This way, you can check alt tags of all images on your website and filter them. For example, if you need to optimize images with “.jpg” filenames, the tool will display it to you like this:

For further reading, I recommend this step-by-step guide on how to audit images of a web site.

Now, you know the basics about alt text, and you also know how to audit it. Let’s move on to the more advanced practices required to overtake your competitors in search engines.

Use Advanced Alt Text Techniques Like a Pro

Different pictures can have different purposes. And sometimes, depending on the context of a web page, the same image can have more than one purpose.

There are three main types of images:

• Informative images: These images are the most important for SEO. They graphically represent concepts and information like photos and illustrations.
• Decorative images: Purpose of an image is to add visual decoration.
• Functional images: An image can have a specific function, in the form of a link or a button.

Informative Images

As said above, if you want to describe an informative image, try to imagine you’re calling your friend; describe it to him in up to 10 words.

What would you say to him if you see this car?

Source: Wikipedia.org.

Source: Pohodo.sk

There are a few simple steps on how to create the best alt text.

Alt text checklist of an informative image:

Alternative text should typically:

• Be as exact as possible
• Be relatively short; up to 10 words, but can be a bit longer if necessary
• Include keywords
• Avoid phrases like “image of” or “123.png”

Decorative Images

Sometimes the only purpose of an image is to add visual decoration to the page. Then, the image should be added to a web page with CSS or alt should be empty (alt=””):

Functional Images

Sometimes an image can have a specific function in the form of a link or a button. Here, the alternative text should describe the functionality of the image. For example, a picture of a search button has a “search” function. Therefore, the alt attribute should contain “search”:

If you want to know more about how to use the right alt text in this case, you can find help here: decision tree from W3.org:

The Conclusion

Informative images like photos and illustrations are most important for SEO. Image SEO holds over 20% of the search engine market share. And the competition isn’t so steep. Take this opportunity!

Don’t forget, when you create alt text, always think about its context. Sometimes, the most important thing about the image is its function. And sometimes the image has only a decorative purpose.

Sources

• https://www.w3.org/WAI/tutorials/images/decision-tree/
• https://www.directom.com/image-seo-using-alt-text/
• https://sparktoro.com/blog/google-ctr-in-2018-paid-organic-no-click-searches/
• https://www.reliablesoft.net/image-seo/
• https://www.w3.org/TR/WCAG10/#gl-provide-equivalents

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Jan Januska

Janko is CEO of the SEO tool Spotibo. He has experience with SEO for e-commerce, press and non-profit websites.

Latest posts by Jan Januska (see all)

• Image SEO: How to Write Powerful Alt Image Tags - November 12, 2019