Alt Text SEO: Why It Matters and How to Do It Right

Alt text, also known as “alternative text,” is an often overlooked yet crucial element of SEO and web accessibility. Properly implemented, it can make your website more accessible to all users, help you rank higher on search engines, and enhance the overall user experience. But what exactly is the alt text, and why is it so important?

This post will explore everything you need to know about alt text—from why it matters for screen readers to tips for writing optimized, SEO-friendly alt text. Whether you’re a webmaster, content creator, or business owner, this guide will help you get it right.

Why Is Alt Text Crucial for Accessibility?

Alt text is a key component in making the web inclusive and accessible for everyone, particularly for individuals who use screen readers due to visual impairments. According to the World Health Organization, over 2.2 billion people globally live with some form of visual impairment, making accessibility a priority for creating an equitable digital experience.

How Screen Readers Use Alt Text?

Screen readers rely on alt text to describe the content of images to users who cannot see them. According to SEO conference speaker, Miracle Inameti-Archibong in a presentation at MozCon,12 million Internet users have a visual impairment or low vision. Well-written alt text provides context and meaning, enabling visually impaired individuals to engage fully with digital content. For example, a product image without descriptive alt text might leave a user unaware of what’s being represented, whether it's a book cover, a pair of shoes, or an infographic with vital data.

The Consequences of Missing Alt Text

Without proper alt text, users relying on assistive technology miss important information, creating a frustrating and incomplete experience. A 2024 Report on Accessibility by WebAIM found that 54.5% of all home pages had missing alternative text for images, making the online world less accessible for millions of people.

Legal Requirements for Accessibility

Accessibility isn’t just a matter of good practice—it’s becoming a legal necessity. Frameworks like the Americans with Disabilities Act (ADA) increasingly define accessible websites as mandatory. In fact, lawsuits related to web accessibility are on the rise, 14,000 web accessibility lawsuits were filed from 2017 through 2022,  with over 3,000 digital accessibility-related lawsuits filed in the U.S. in 2022 alone.

The Benefits of Inclusive Design

By including detailed, descriptive alt text, you not only comply with legal requirements but also expand your reach to a broader audience. Accessible websites are more user-friendly for everyone, and they demonstrate a commitment to inclusivity and social responsibility.

Provides Context for Image Search

Alt text plays an essential role in image search by allowing search engines to understand what the image represents, as they can't "see" the image the way humans do. You’ll see image packs appear in search results when Google determines that the query is best supported by visual content.

Visual search simplifies finding what you need, whether you’re unsure of what you’re looking for, seeking visual inspiration, or refining your search with clearer guidance. This makes images more searchable and accessible while improving a website's SEO.

Adding alt text isn't just a small task—it’s a meaningful step towards ensuring your content is accessible to all. With the number of visually impaired individuals on the rise, creating an inclusive web experience has never been more important. Make your content count by bridging the gap with properly written alt text.

What Does Alt Text Look Like in HTML?

Understanding how alt text is implemented in HTML is key to using it effectively on your website. Alt text is added as an attribute within an '<img>' tag, which is used to embed images in a webpage's code. Here's a basic example of what alt text looks like in HTML:

'''

<img src="example-image.jpg" alt="A red apple on a wooden table">

'''

In this example:

• 'src="example-image.jpg"' specifies the path or URL of the image file.
• 'alt="A red apple on a wooden table"' provides the descriptive alternative text for the image.

The description within the 'alt' attribute should be concise and clearly explain the content or purpose of the image.

Image Source: Moz

This helps screen readers convey the intended message to users with visual impairments, while also benefiting search engines by providing context about the image.

It’s important to note that if an image is purely decorative and does not add essential information to the page, the 'alt' attribute should be left empty, like this:

'''

<img src="decorative-image.jpg" alt="">

'''

This practice ensures that screen readers skip over decorative images, focusing instead on meaningful content. Writing effective alt text begins with understanding your target audience and the role each image plays in the broader context of your website.

Steps to Add Alt Text to Images

Adding alt text to images involves a series of straightforward steps, but it requires thoughtful consideration to ensure the text is both descriptive and effective. Here's a detailed explanation of how to do it right, step by step:

1. Understand the Purpose of the Image

Before writing alt text, determine the purpose of the image within the context of your webpage. Ask yourself:

• Is the image informational (e.g., a graph or product image)?
• Is the image purely decorative (e.g., a background pattern or design element)?

The purpose of the image will dictate how you approach writing the alt text. Informational images need descriptive alt text, while decorative images should use an empty alt attribute (alt="").

2. Write Descriptive Yet Concise Alt Text

Keep your alt text straightforward and concise while effectively describing the image. Avoid overloading the text with unnecessary details, and focus on what is essential for understanding the image’s role on the page. For example:

• Good Alt Text: "A woman holding a blue umbrella in a rainy park."
• Bad Alt Text: "A woman standing in a park holding a blue umbrella while it rains lightly, with trees, grass, and a bench in the background."

3. Avoid Starting With 'Image of' or 'Picture of'

Screen readers automatically announce the presence of an image, so there’s no need to start your alt text with phrases like "Image of" or "Picture showing." Instead, jump straight into describing the content.

4. Include Keywords for SEO (Where Appropriate)

When relevant, include keywords naturally in your alt text to enhance SEO value. However, avoid keyword stuffing. Your primary goal should always be to write descriptive alt text that serves the user's needs. For instance:

• SEO-Optimized Alt Text: "Wooden dining table with a modern minimalist design."
• Overdone Alt Text (Keyword-stuffed): "Table, wooden dining table, dining table modern design, wooden modern table."

5. Use Empty Alt Attributes for Decorative Images

If an image is purely decorative and doesn’t contribute to the content, use an empty alt attribute (alt="") to prevent screen readers from announcing it. This ensures the user experience is not cluttered with irrelevant information.

Example:

'''

<img src="decorative-pattern.jpg" alt="">

'''

6. Implement Alt Text in Your CMS or HTML

Depending on your platform, you can add alt text directly through your Content Management System (CMS) or within your website’s raw HTML code:

Using a CMS (like WordPress, Squarespace, or Shopify):

• Locate the image upload or media section of your CMS.
• Click on the image you want to edit.
• Enter or edit the alt text field provided. Save your changes.

Using HTML Code:

 Add the 'alt' attribute to the '<img>' tag like this:

 '''

 <img src="example-image.jpg" alt="A detailed illustration of a solar panel on a rooftop.">

 '''

7. Test With a Screen Reader

After adding alt text, test your website with a screen reader to ensure the text conveys the intended meaning to visually impaired users. Popular screen readers like NVDA (Windows) or VoiceOver (Mac) can help you experience how users interact with your alt text.

8. Regularly Audit and Update Alt Text

Web content changes over time, and your alt text should stay up to date. Conduct periodic audits of your images to ensure the descriptions are still relevant and accurate. Remove any instances of missing or low-quality alt text.

Image Source: Reliablesoft

By following these steps, you can confidently create alt text that enhances accessibility, boosts your SEO, and improves the overall user experience on your website. Taking the time to write thoughtful alt text ensures your digital content is inclusive, effective, and impactful.

What Does Effective Alt Text Look Like?

Not all alt text is created equal. Here’s a comparison of poor vs. optimized alt text:

Bad Alt Text

• "Image" 
• "Cat"

Good Alt Text

• "A gray tabby cat sleeping on a patterned rug in the sunlight"

Notice how the second example goes beyond stating the obvious and includes relevant details, offering more context. This helps both screen readers and search engines understand the specific content and purpose of the image.

How Long Should Alt Text Be?

While there isn't a strict character limit for alt text, it’s advisable to keep it concise, ideally under 125 characters. Screen readers typically stop after this length, so brevity is key.

What About Decorative Images?

For purely decorative images, where alt text doesn’t add any value (e.g., a background graphic or a separator line), use null alt text by setting alt="". This tells screen readers to skip the image entirely, improving usability for visually impaired users.

Example:

'''

<img src="decorative-pattern.png" alt="">

'''

Is Alt Text a Google Ranking Factor?

Yes, alt text contributes to SEO as a ranking signal. Search engines like Google use alt text to understand the content and context of images, making it a valuable tool for optimizing your site. By including alt text, you increase the likelihood of your images appearing in Google Image Search, bringing more traffic to your site.

Image Source: SearchPilot

Well-crafted alt text also reinforces your page's topic, which can enhance your overall ranking for relevant keywords.

Tips for Writing Optimized Alt Text

Here are seven practical tips to ensure your alt text is both user-friendly and SEO-ready:

1. Be Specific and Descriptive

When writing alt text, describe what’s in the image with as much detail as necessary to convey its purpose. This helps users with visual impairments understand the image better. For example, instead of simply writing “dog,” you could write “a golden retriever running on a beach at sunset, carrying a stick in its mouth.” Adding context like location, action, or mood provides more value.

2. Use Keywords Strategically

If you’re optimizing for SEO, include your target keyword in the alt text, but make sure it feels natural and relevant to the image. For instance, if your target keyword is "beach vacation," you could write “families enjoying a beach vacation with colorful umbrellas and clear blue skies.” However, avoid keyword stuffing, as it can make the text nonsensical and diminish the user experience.

3. Consider the Context

Always think about the role the image plays on the page. Why is it there, and what does it add to the surrounding content? Tailor your alt text to reflect how the image complements the topic. For example, if the page discusses eco-friendly gardening, an image of a compost bin could use alt text like “a wooden compost bin filled with organic waste in a backyard garden.”

4. Avoid Starting With “Image of” or “Picture of”

Screen readers already identify the element as an image, so there’s no need to start your alt text with phrases like “Image of” or “Picture of.” Jump straight into the description to save space and make the text more effective. For example, instead of “Image of a bouquet of roses,” simply write “a bouquet of red roses in a glass vase.”

5. Keep It Short but Informative

Good alt text strikes a balance between being concise and including enough information to provide value. Ideally, keep your alt text under 125 characters, as screen readers may truncate longer descriptions. Focus on the essentials, like “a toddler playing with building blocks on a living room carpet,” rather than overloading the text with unnecessary details.

6. Mind Decorative Images

Decorative images, such as background patterns or visual accents, don’t contribute to the content’s meaning. Use alt="" for these images to signal to screen readers that they can skip over them, reducing unnecessary information for users. For example, if your page has a decorative flourish around a heading, it doesn’t need descriptive alt text.

7. Include Text in Complex Images

For graphs, charts, or infographics, summarize the most important information in the alt text so users can grasp the key points. For example, a bar chart showing quarterly sales growth might use alt text like “bar chart showing a 20% increase in sales from Q1 to Q2.” If the image contains too much detail to summarize effectively, provide a more detailed explanation in the surrounding text or a caption.

By following these tips, you can create alt text that not only supports accessibility but also enhances the context of your content for all users. Thoughtful alt text improves usability, SEO, and the overall effectiveness of your website.

Further Reading: Optimizing Your Images for Better Search Results

Additional Tips to Maximize the Impact of Alt Text

• Test your website using accessibility tools like WAVE or Lighthouse to identify missing or poorly written alt text.
• Train your team on the importance of alt text to ensure consistency.
• Regularly audit your site to update alt text, especially after content changes.

How DashClicks' SEO Services Can Help Implement Alt Text?

DashClicks offers comprehensive white label SEO services tailored to enhance your website's accessibility and search engine optimization, including implementing effective alt text.

Our team of SEO experts ensures that every image on your site is aligned with best practices, using concise, descriptive, and keyword-optimized alt text that enhances user experience and supports your SEO strategy.

Whether it’s analyzing image purposes, writing meaningful descriptions, or ensuring compliance with accessibility guidelines, the best white label SEO services provides the tools and expertise you need to make your content inclusive and search-engine friendly.

With regular audits and updates, we help keep your alt text optimized for both users and search algorithms.

Alt Text: A Small Detail That Has a Big Impact

Alt text isn't just about meeting accessibility standards; it’s about creating a more inclusive and effective website for everyone. From improving user experience to driving organic traffic, the benefits of well-thought-out alt text are worth the effort.

Start optimizing your images today and watch as your website becomes more accessible and SEO-friendly—one description at a time!