The Importance of Alt Tags for SEO and Accessibility

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Mimi Phan

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You may have heard of the phrase “a picture is worth a thousand words,” but have you ever considered how search engines and visually impaired users interpret images on your website?

That’s where alt tags come in. Alt tags, short for alternative tags, are HTML attributes that provide image text descriptions. Not only do they help improve the accessibility of your website, but they also play a vital role in search engine optimization (SEO).

In this post, we’ll explore the importance of alt tags, how they benefit your website, and how to implement them effectively.

What is Alt text?

Alt text, or alternative text or alt tags, is a textual description added to an HTML image tag. It describes the appearance and function of an image on a web page for visually impaired users or who have images turned off in their web browser.

Alt text should be brief and accurate, conveying the essential information of the image. This text also helps search engines understand what the image is about, which can improve the image’s visibility in search results.

In short, alt text is an essential tool to make web content more accessible and enhance the user experience for all visitors to a website.

Image Alt Text Best Practices

In the end, picture alt text must be precise while also being indicative of the subject of the webpage it supports. The following guidelines will help you create successful image alt text:

Keep Alt Text 125 Characters or Less

Keep your alt text to fewer than 125 characters; screen readers and other assistive technologies cease reading alt text at this point. When describing this for the visually impaired, cut off long-winded alt text at awkward times.

To avoid having your alt text cut off, it’s best to keep it at this maximum.

Include One Major Relevant Keyword

This may go against what we previously suggested. However, if it gives context for the page the picture is on, it’s a good idea to include a primary keyword in your alt text.

The target keyword frequently serves as extra context and information, which is the purpose of alt text.

You can also use variants of your primary keyword to make it sound more natural.

Alt Text for Decorative Pictures Should Not Be Included

While the purpose of alt text is to give pictures as much context as possible, some images don’t require any additional explanation.

There is no requirement to include alt text for decorative images like icons, horizontal page breaks, a magnifying glass icon in a search box, etc.

Screen readers can understand the page without knowing what these images look like, and Google does not require additional context or information to rank the website.

Keep Your Term Usage to a Minimum.

If your alt text makes it possible, only use the goal keyword for your article. If not, consider using only the most crucial phrases within a longtail or semantic keywords. For instance, you might use “lead generation” in your alt text if your article’s head keyword is “how to produce leads,” as it might be challenging to naturally include “how to” in the image alt text.

Don’t Include “Image of” or “Picture of” in Alt Text

Avoid beginning your meta text with “picture of” or “image of.” Go straight to the description of the picture. From the article’s HTML source code, screen-reading software (and Google, for that matter) will recognize it as a picture.

Not Every Picture Needs to have Alt text.

For SEO, user experience, and accessibility, you should usually add alt text to webpage pictures, but there are some exceptions. An empty alt attribute, for instance, should be used for images only for decoration or explained in the surrounding text. Check out this decision tree for a more thorough explanation of when to add image text and when to avoid doing so.

Check for spelling mistakes.

Misspelled words in the alt text of your images may detract from the user experience or confound web crawlers. Like any other content on the website, alt text needs to be reviewed.

How Alt Text Affects SEO

According to Google, alt text is used to interpret the topic matter of images in conjunction with computer vision algorithms and the page’s contents.

Thus, alt text aids Google in comprehending the webpage’s overall theme and the subject matter of the pictures. This can increase the likelihood that your images will appear in image search results.

When writing content on a subject, consider how your target audience might prefer to research answers to their queries. For example, Google searchers often prefer the picture on your website rather than the standard blue, hyperlinked search result.

Why is Image Alt text Important?

For reasons of accessibility, user experience, and picture traffic, image alt text is crucial. You can create the best alt text for your pictures by being aware of these factors. We’ll examine why picture alt text is vital in more detail below.


One principle of accessible online design is alt text. Its initial (and still current) primary objective is to provide visitors who are blind with descriptions of images.

Users who are blind or otherwise unable to recognize an image directly are included in this, as are screen readers and browsers blocking images.

All users, regardless of visual ability, can understand and enjoy the information on your website by including alt text with each of your images.

User Experience

alt text benefits all users. For example, imagine a visitor to your website has a slow internet link, preventing the images from loading. They’ll see the alt text and missing link icon. This will let them understand the message the image was trying to communicate.

Image Traffic

Turning your pictures into hyperlinked search results in Google Images or as image packs is one of the most crucial things image alt text can do for you. The #1 spot on a SERP, as seen in the example in the introduction, is one organic position where image packs, which are special results displayed as a horizontal row of image links, may show.

Another method to get organic traffic comes from images in image packs or Google Images.

Image search SEO

Along with enhancing user experience and accessibility, using picture alt text can also benefit your SEO explicitly and implicitly. Making sure your images are search-engine optimized will help them appear higher in image packs and image searches.

Prioritize making sure images appear when users type text-based searches when you are optimizing for image search. To achieve this, adhere to picture SEO best practices such as:

  • Lastest file formats
  • Alt text
  • Relevant file titles
  • HTML Structure

This enables Google to recognize your website’s images more accurately and deliver a relevant image search result.

Though search crawlers still can’t “see” the pictures on a website page the way we can, it’s not advisable to leave the interpretation entirely in their hands, even though search engine image recognition technology has significantly improved over the years.

If they misunderstand or get it incorrect, you run the risk of either ranking for unintended keywords or not ranking at all.

How Important is Alt text?

In addition to following best practices for image naming and title, including alt text guarantees that both humans and robots can comprehend the content of your website.

You have a second chance to use your goal keyword in the alt text. It’s in your best interest to create alt text that describes the image and contains a keyword or phrase you’re targeting because on-page keyword usage still counts as a search engine ranking factor.

Giving Google accurate information about your images is an excellent way to convey subject relevance if traffic from image searches is a crucial component of your SEO strategy. You can achieve this by utilizing contemporary file formats, alt text, proper file names, and schema markup.

How Do I Write Good Alt Text?

How Do I Write Good Alt text - iRocket VC

Explain the picture as precisely as you can.

The primary purpose of alt text is to provide text descriptions of images for viewers who cannot see them. If an image is purely decorative or is only present for design reasons and does not communicate any meaning or value, it belongs in the CSS and not the HTML.

Make it (relatively) brief.

Alt content should be limited to 125 characters or less. Popular screen readers are known to terminate alt text after about 125 characters. Although it is no longer an absolute requirement, it is still helpful guidance for SEOs and content producers. See point 7 below for guidelines on writing alt text for complex images that need lengthier descriptions.

Add your keyword(s)

You have a second chance to use your target keyword on a page with alt text, giving you a chance to tell search engines that your page is highly pertinent to a specific search query. While describing the image and giving it context should come first, put your keyword in the alt text of at least one image on the website.

Avoid keyword Stuffing.

Google won’t penalize you for having subpar alt text, but you’ll get into trouble if you use it to jam in as many pertinent keywords as possible. Leave it to write evocative alt text that contextualizes the picture and, if possible, incorporates your target keyword.

Avoid using pictures as text.

This is more of a general SEO-friendly web development principle than a best practice unique to alt text. You should refrain from using images instead of words because search engines cannot read the text within your images. If you must, describe in your alt text what your picture is saying.

Keep “image of,” “picture of,” etc., out of your secondary text.

You don’t need to indicate that your alt text refers to an image because that is already assumed.

For complex pictures, follow best practices.

Using accessibility best practices, describe maps, charts, diagrams, and other complicated images. Although different browsers interpret the longdesc=” attribute differently, screen reader users can still use it.

Don’t forget about form icons.

Give an alt property to images used as the “submit” buttons on your website’s forms. The alt tag on the image buttons should include a description of the button’s purpose, such as “search,” “apply now,” “sign up,” etc.

Implementing alt tags is a simple yet powerful way to improve both the accessibility and SEO of your website. By providing clear and concise descriptions of your images, you can make your content more accessible to all users, including those who are visually impaired.

At the same time, you can enhance your website’s visibility in search engine results, driving more traffic to your site.

So, take the time to ensure that your alt tags are descriptive, accurate, and optimized for SEO. Your users (and your website’s ranking) will thank you for it!