What Is Alt Text: A Comprehensive Guide to Web Accessibility

Published on 10/31/2023
Matrix movie still


In an increasingly digital world, where images and visuals are a significant part of online content, ensuring web accessibility and inclusivity is paramount. One of the essential elements in this endeavor is “alt text.” If you’re unfamiliar with the term, don’t worry; we’re here to shed light on it. Alt text, short for alternative text, is a simple yet powerful tool that makes the online universe more inclusive and accessible for everyone.

The Importance of Web Accessibility and Inclusivity

Web accessibility goes beyond mere convenience; it’s a matter of basic human rights. Ensuring that digital content is available and understandable to all, including those with visual impairments, is a crucial step toward a more inclusive internet. In a world where information is readily available at our fingertips, no one should be left in the dark due to a disability.

What This Blog Post Will Cover

In this comprehensive guide, we’ll delve into the concept of alt text and its role in web accessibility. We’ll explore the technical aspects of alt text, its practical applications, and why it’s vital for individuals with visual impairments. We’ll also discuss its significance for SEO, providing best practices, real-world examples, and practical tips for crafting effective alt text.

So, whether you’re a web developer, content creator, or just someone eager to make the internet a more inclusive place, this blog post is for you. Let’s embark on a journey to understand and implement alt text, ensuring that no one is left behind in the digital landscape.

The Role of Alt Text in Web Accessibility

Alt text, or alternative text, serves as a bridge to a more inclusive digital world. Its significance in web accessibility cannot be overstated, and in this section, we’ll explore just how vital it is in ensuring everyone can access and understand online content.

Contributing to Web Accessibility

Web accessibility is all about making digital content available and comprehensible to individuals with disabilities, including those with visual impairments. Alt text plays a pivotal role in this endeavor by providing a textual description of images, allowing screen readers and other assistive technologies to convey the visual content to those who can’t see it.

Alt text doesn’t just enhance accessibility; it’s a key component of it. By adding this descriptive text to images, websites become more welcoming to a broader audience, fostering a digital environment that’s accessible to all, regardless of their abilities.

Legal Requirements and Standards

To underscore the importance of web accessibility, legal requirements and standards have been put in place. Two prominent benchmarks in this domain are the Americans with Disabilities Act (ADA) and the Web Content Accessibility Guidelines (WCAG).

  • Americans with Disabilities Act (ADA): Enacted in 1990, the ADA is a landmark piece of legislation that prohibits discrimination on the basis of disability. While it primarily addresses physical spaces, it also extends to digital environments, ensuring that websites and online services are accessible to individuals with disabilities. This legal framework underscores the necessity of alt text as a fundamental tool in web accessibility.
  • Web Content Accessibility Guidelines (WCAG): Developed by the World Wide Web Consortium (W3C), the WCAG provides a set of guidelines for creating accessible web content. It is globally recognized and serves as a reference point for organizations and web developers striving to make their digital offerings more inclusive. WCAG emphasizes the role of alt text as one of the critical success criteria in ensuring web accessibility.

Incorporating alt text is not just a good practice; it’s a legal requirement and a moral imperative. As we continue our journey through this guide, we will delve deeper into the technical aspects of alt text and explore its practical applications, providing you with the knowledge and tools to create a more inclusive online experience.

How Alt Text Works

Alt text is more than just a concept; it’s a fundamental aspect of HTML and web design that empowers web accessibility. In this section, we’ll delve into the technical aspects of alt text in HTML, providing you with a practical understanding of how it functions and where it can be applied.

The Technical Aspect of Alt Text in HTML

Alt text is an attribute within HTML tags used to provide a textual description of an image or other non-text elements. It is primarily used in the <img> (image) tag, but can also be applied to other HTML elements like <input>, <area>, and <applet>. The alt attribute is crucial for screen readers and other assistive technologies, as it enables them to convey the content and purpose of an image to users who may not be able to see it.

Here’s an example of how the alt text attribute is used in HTML code:

<img src="example.jpg" alt="A red balloon floating in a clear blue sky">

In this example, the “alt” attribute contains a brief, descriptive text that conveys the content of the image. It’s important to ensure that alt text is concise yet informative, providing an accurate representation of the image.

Where Alt Text Can Be Applied

Alt text is not limited to images alone. It can be applied to various HTML elements, enhancing accessibility across different types of content. Common use cases for alt text include:

  1. Images: As previously mentioned, providing alt text for images is a standard practice to make visual content accessible to screen reader users.
  2. Buttons and Icons: Alt text can be used with buttons and icons to convey their function or purpose. For example, an icon representing a “Search” function can have alt text like “Search icon.”
  3. Form Fields: Alt text can be used with form input elements like text fields and buttons to ensure that users with visual impairments understand the purpose of each field.
  4. Image Maps: In cases where images are divided into clickable regions (image maps), alt text helps users understand the function of each clickable area.

Understanding where and how to apply alt text is crucial to ensure comprehensive web accessibility. In the next sections, we’ll explore best practices for crafting effective alt text and its broader implications, including its role in SEO and web accessibility standards.

Crafting Effective Alt Text

Crafting effective alt text is an art in itself, and it plays a pivotal role in ensuring web accessibility. In this section, we’ll delve into the characteristics of good alt text, discuss what to avoid, provide practical tips and guidelines, and showcase examples of well-written alt text.

Characteristics of Good Alt Text

Good alt text possesses several key characteristics:

  1. Descriptive: It accurately describes the content and purpose of the image or element it is associated with. It should answer the question, “What is in the image?” or “What does this element do?”
  2. Concise: It is brief and to the point while conveying all the necessary information. Avoid being overly verbose or including unnecessary details.
  3. Relevant: Alt text must be relevant to the context of the page. It should contribute to the understanding of the content and its intended message.
  4. Non-repetitive: If an image appears multiple times on a page for the same purpose, the alt text should be the same for each instance to maintain consistency.
  5. Not overly technical: Avoid using technical jargon or terms that may not be familiar to all users. Keep the language simple and accessible.

What to Avoid When Writing Alt Text

While creating alt text, it’s essential to steer clear of common pitfalls that can hinder accessibility:

  1. Redundancy: Do not include phrases like “image of” or “picture of” as it is redundant and provides no additional information.
  2. Spammy Keywords: Avoid keyword stuffing in alt text for SEO purposes. Alt text should prioritize accessibility over search engine optimization.
  3. Blank or Missing Alt Text: Leaving the alt text blank or missing it entirely can be just as detrimental as poor alt text. It leaves screen reader users with no information about the image.
  4. Non-informative Alt Text: Alt text like “image123” or “placeholder” doesn’t provide meaningful information. It’s essential to be specific.

Tips and Guidelines for Creating Meaningful Alt Text

Here are some practical tips and guidelines to create alt text that truly enhances web accessibility:

  1. Put Yourself in the User’s Shoes: Imagine you are blind or visually impaired and ask yourself what information you would need to understand the content and context of the image.
  2. Keep It Short and Sweet: Alt text should be concise. Aim for a few words or a short sentence that captures the essence of the image.
  3. Use Keywords Sparingly: While it’s crucial to include relevant keywords, avoid overloading the alt text with keywords. Prioritize clarity and meaning.
  4. Avoid Decorative Images: For purely decorative images that don’t convey meaningful content or functionality, use empty alt text (alt=””) to indicate they are for visual aesthetics only.
  5. Identify Functionality: If an image serves a functional purpose, like a “Submit” button in a form, ensure the alt text describes that function, e.g., “Submit Form.”

Showcasing Examples of Well-Written Alt Text

  1. Example 1 – Descriptive Alt Text: For an image of the Eiffel Tower, a good alt text would be: “The Eiffel Tower in Paris, France.”
  2. Example 2 – Functional Alt Text: For a “Like” button, the alt text can be as simple as “Like.”
  3. Example 3 – Informational Alt Text: For a pie chart representing website traffic, the alt text might be: “Pie chart showing website traffic distribution – 40% direct, 30% search, 20% referral, 10% social.”

These examples illustrate how effective alt text can be both descriptive and concise, making the content more accessible to individuals with visual impairments. Crafting alt text that strikes the right balance between clarity and brevity is an essential part of promoting web accessibility and inclusivity.

The Impact of Alt Text on SEO

Alt text isn’t just a tool for web accessibility; it also wields a significant influence on search engine optimization (SEO). In this section, we’ll explore how alt text can impact your website’s SEO, the importance of descriptive alt text for image SEO, and the connection between web accessibility and search engine rankings.

How Alt Text Influences Search Engine Optimization

Search engines rely on text to understand the content of a webpage. When it comes to images, search engine crawlers cannot “see” them in the same way humans do. This is where alt text comes into play. Alt text serves as a textual description of images, enabling search engines to comprehend the image’s content and relevance to the page’s topic.

Here’s how alt text impacts SEO:

  1. Improved Indexing: Alt text allows search engines to index images properly, making them more discoverable in image search results.
  2. Keyword Relevance: Descriptive alt text that includes relevant keywords can enhance the keyword relevance of a page, potentially improving its ranking for those keywords.
  3. Enhanced User Experience: By providing alt text, you ensure that your website is more accessible to a broader audience, including those with visual impairments. A better user experience can indirectly boost your site’s SEO.

The Importance of Descriptive Alt Text for Image SEO

For image SEO, the quality of alt text matters significantly. Descriptive alt text provides valuable information about the image’s content and purpose. When creating alt text for images, keep these considerations in mind:

  1. Be Descriptive: Provide a clear and accurate description of the image. For example, if the image shows a “Vintage Red Bicycle,” use that as your alt text.
  2. Incorporate Keywords: If relevant, include keywords that relate to the image and the page’s content. This can enhance the page’s visibility in search results.
  3. Avoid Keyword Stuffing: While keywords are essential, don’t overdo it. Alt text should prioritize user experience and accessibility over SEO.

The Connection Between Web Accessibility and Search Engine Rankings

Search engines aim to provide the best possible results to users. As such, they reward websites that offer a positive user experience, and web accessibility is a crucial part of this experience. When your website is more accessible, it becomes more user-friendly, which can positively impact your search engine rankings.

Here’s how web accessibility and SEO are connected:

  1. Lower Bounce Rates: Web accessibility measures, including alt text, can lead to a more inclusive and engaging user experience, reducing bounce rates and signaling to search engines that your content is valuable.
  2. Extended Dwell Time: When your content is accessible, it can attract and retain a broader audience, increasing the amount of time visitors spend on your site, a factor search engines consider.
  3. Higher Quality Backlinks: Websites that are committed to accessibility are more likely to attract natural, high-quality backlinks from authoritative sources, which can improve SEO.

In summary, alt text is a bridge between web accessibility and SEO. By providing descriptive and meaningful alt text, you can enhance the user experience for all visitors while also boosting the visibility and search engine ranking of your website. It’s a win-win scenario where accessibility and SEO go hand in hand.

Alt Text Best Practices

Alt text, when done right, can significantly enhance web accessibility and user experience. Here’s a comprehensive list of best practices for writing alt text, complete with real-world case studies and examples, as well as tools and resources to help you test and improve your alt text.

Best Practices for Writing Alt Text:

  1. Be Descriptive: Provide a concise and accurate description of the image’s content or function. Think about what information a user would miss if the image were not visible.
  2. Context Matters: Consider the context of the image within the content. The alt text for a decorative image should differ from that of an informative chart.
  3. Keep It Concise: Alt text should be brief, focusing on the most critical information. Aim for a few words or a short sentence.
  4. Avoid Repetition: If an image is repeated, use the same alt text to maintain consistency across the website.
  5. Functional Images: For images like buttons or icons, describe the action they perform, such as “Play Video” or “Download File.”
  6. Decorative Images: For purely decorative images, use empty alt text (alt=””) to indicate their decorative purpose to screen readers.
  7. Captions and Context: If an image has a caption, the alt text should provide a summary of the image, while the caption provides additional context.
  8. File Format and Size: Describe the content, not the file format or size. Avoid phrases like “image of” or “small red flower.”
  9. Check for Redundancy: Avoid including information that is already present in the surrounding text.

Real-World Case Studies and Examples:

Case Study 1: eCommerce Website

A study conducted on an eCommerce website showed that products with descriptive alt text had a 20% higher click-through rate compared to those without alt text. Customers could make more informed decisions, leading to increased engagement and sales.

Case Study 2: Educational Platform

An educational platform implemented detailed alt text on course materials. This led to a 15% improvement in student engagement among visually impaired students, showcasing how alt text directly impacted the learning experience.

Tools and Resources for Testing and Improving Alt Text:

  1. WAVE (Web Accessibility Evaluation Tool): WAVE allows you to test your website for accessibility issues, including missing or poorly written alt text.
  2. axe Accessibility Checker: This browser extension identifies accessibility issues, providing detailed explanations and solutions, including alt text improvements.
  3. A11Y CSS Reset: A set of CSS rules that help developers prevent common accessibility issues, ensuring that images are accessible to all users.
  4. User Testing: Conduct usability tests with individuals who rely on screen readers to gather direct feedback on the effectiveness of your alt text.
  5. WCAG Guidelines: Refer to the Web Content Accessibility Guidelines (WCAG) for comprehensive standards and best practices regarding alt text and other accessibility features.

By adhering to these best practices, studying real-world case studies, and utilizing accessible design tools, you can create a web environment where alt text not only meets standards but also enhances user experience, making your content accessible and meaningful to all users.

Alt Text in Different Contexts

Alt text isn’t limited to just web pages. It plays a vital role in various digital environments, from social media and email to mobile apps. In this section, we’ll explore how alt text is used in these different contexts and why maintaining consistency in alt text usage across platforms is crucial.

Alt Text in Social Media:

Social media platforms have embraced alt text to enhance accessibility. Users can add alt text to images they upload, ensuring that their content is accessible to everyone, including those with visual impairments. This feature enables users to describe their images, making the platform more inclusive. As a best practice, social media users should provide meaningful alt text for their images, whether it’s a tweet, Instagram post, or Facebook update.

Alt Text in Emails:

Emails often contain images, and including alt text is essential for accessibility. Many email clients support alt text, allowing users to provide descriptions for images within their email content. This ensures that recipients with visual impairments can understand the images, such as product promotions or event invitations. Email marketers and designers should prioritize alt text for images to create more inclusive email campaigns.

Alt Text in Mobile Apps:

Mobile apps, whether for shopping, communication, or entertainment, also incorporate images and icons. App developers should implement alt text to describe these elements, improving accessibility for users who rely on screen readers. A consistent approach to alt text in mobile apps is fundamental to delivering an inclusive user experience.

Importance of Consistency Across Platforms:

Maintaining consistency in alt text usage across various digital platforms is essential for several reasons:

  1. Uniform Accessibility: Ensuring that alt text is used consistently across different platforms guarantees that users with visual impairments encounter a similar level of accessibility regardless of where they access digital content.
  2. Streamlined User Experience: Users who are familiar with how alt text works in one environment will find it easier to navigate and comprehend content in other environments when they encounter consistent alt text practices.
  3. Compliance with Standards: Consistency in alt text usage helps ensure adherence to accessibility standards and guidelines, such as WCAG. This can be particularly important for organizations and businesses aiming to comply with legal requirements.
  4. Broader Inclusivity: A consistent approach to alt text expands inclusivity to a broader audience, making the digital space more welcoming to individuals with diverse abilities.

In conclusion, alt text is not confined to web pages but extends to social media, email, and mobile apps, fostering accessibility in various digital environments. Consistency in alt text usage across these platforms is vital to ensure that all users, regardless of the platform they’re using, can enjoy an inclusive and accessible digital experience.

Implementing Alt Text

Adding alt text to images is a straightforward process, and it’s crucial for web accessibility. In this section, we’ll provide step-by-step instructions on how to add alt text to images in different content management systems (CMS), such as WordPress, Drupal, and Wix.

Adding Alt Text in WordPress:

  1. Login to Your WordPress Dashboard: Access your website’s admin area by logging in.
  2. Edit or Add a Post/Page: Choose an existing post or page to edit or create a new one.
  3. Insert an Image: Click on the “Add Media” button to insert an image into your post or page.
  4. Edit the Image: After uploading or selecting an image, click on it. You’ll find an “Edit” button – click on it.
  5. Add Alt Text: A window will pop up with image details. Here, you can add your alt text in the “Alternative Text” field.
  6. Update the Image: Save your changes by clicking the “Update” or “Save” button, and the alt text will be associated with the image.

Adding Alt Text in Drupal:

  1. Log In to Your Drupal Admin Panel: Access your website’s admin area by logging in.
  2. Edit or Add Content: Choose the content where you want to add an image.
  3. Insert an Image: Use the image upload or selection tool within the content editor.
  4. Add Alt Text: When adding or editing an image, look for the alt text field. Enter your alt text here.
  5. Save Your Content: Save or update your content to ensure the alt text is associated with the image.

Adding Alt Text in Wix:

  1. Access Your Wix Dashboard: Log in to your Wix account and access the website you want to edit.
  2. Edit the Page: Navigate to the page you wish to add an image to or edit an existing one.
  3. Insert an Image: Use the “Add” button or the image element in the Wix editor to insert an image.
  4. Edit the Image: Once the image is inserted, click on it to edit its properties.
  5. Add Alt Text: In the image properties window, look for the “Alternative Text” field, where you can add your alt text.
  6. Save Your Changes: Save the image properties, and the alt text will be applied to the image.

Remember that the specific steps may vary slightly based on the version of the CMS you’re using. It’s essential to make alt text a standard practice when adding images to your content, ensuring that your website is accessible to everyone, regardless of the CMS you use.

Challenges and Common Mistakes

While implementing alt text is essential for web accessibility, it comes with its set of challenges and common mistakes. In this section, we’ll address the difficulties that writers and web developers often encounter when working with alt text and discuss how to avoid the most common errors.

Challenges When Implementing Alt Text:

  1. Subjective Interpretation: Describing images accurately can be challenging, especially when an image is open to interpretation. Different users may perceive images differently, making it hard to provide a universally acceptable description.
  2. Long Descriptions: Striking the right balance between providing a detailed description and maintaining brevity can be tricky. Long alt text can overwhelm users, while overly concise alt text may lack context.
  3. Dynamic Content: Alt text for dynamic or interactive content like charts and graphs can be complex. Describing changes in real-time data or user interactions can be challenging.
  4. Consistency Across a Team: In collaborative environments, ensuring that alt text is consistent can be a challenge. Writers and developers must communicate effectively to maintain uniform alt text practices.

Common Mistakes and How to Avoid Them:

  1. Blank Alt Text: A prevalent mistake is leaving alt text blank or missing it entirely. Always provide alt text for every image, as missing alt text can make the content inaccessible for users relying on screen readers.
  2. Overloaded with Keywords: Avoid stuffing alt text with keywords for SEO purposes. While keywords are essential, they should not compromise the clarity and relevance of the alt text.
  3. Redundancy: Repeating the same alt text for multiple instances of an image can be a mistake. Instead, provide unique descriptions if the context varies.
  4. Ambiguity: Vague or overly generic alt text like “image” or “icon” is another common error. Be specific and provide meaningful descriptions.
  5. Omitting Decorative Images: For decorative images, it’s incorrect to leave the alt text empty. Instead, use alt text like “Decorative image” to convey its non-functional nature.

How to Address Challenges and Avoid Mistakes:

  1. User Testing: Engage users with visual impairments in usability testing to gather feedback on the effectiveness of your alt text.
  2. Collaboration: Foster effective communication between writers and web developers to ensure consistency in alt text practices.
  3. Educate Your Team: Provide training and guidelines to writers, designers, and developers to help them understand the principles of creating effective alt text.
  4. Consult WCAG: Refer to the Web Content Accessibility Guidelines (WCAG) for detailed guidance on alt text and other accessibility features.

Alt text may present challenges and common pitfalls, but with awareness and a commitment to best practices, it is possible to create accessible and inclusive content that benefits all users. It’s important to continually learn and adapt to the evolving landscape of web accessibility, promoting a more accessible online experience for everyone.

The Future of Alt Text

As the digital landscape continues to evolve, so too does the role of alt text in web accessibility. Here, we’ll look ahead to emerging technologies and trends in web accessibility, exploring what the future may hold for alt text usage.

Emerging Technologies and Trends in Web Accessibility:

  1. Artificial Intelligence (AI): AI-powered tools are becoming increasingly adept at recognizing and describing images. These technologies have the potential to automate the alt text generation process, making accessibility more efficient.
  2. Enhanced Natural Language Processing: Improvements in natural language processing will enable better context recognition and more nuanced alt text descriptions. This will benefit users by providing more informative and user-friendly descriptions.
  3. Machine Learning for Content Optimization: Machine learning algorithms will help content creators and web developers optimize alt text based on user interactions and preferences, tailoring descriptions to individual needs.

Developments and Changes in Alt Text Usage:

  1. Integration with Virtual and Augmented Reality: As VR and AR technologies become more prevalent, alt text may extend to describe elements within virtual or augmented environments, enhancing accessibility in these new digital realms.
  2. Inclusivity for Multimedia Content: Alt text will extend beyond images to include multimedia content like videos and animations, ensuring a comprehensive accessible experience.
  3. Global Accessibility Standards: With an increasing focus on web accessibility, there may be more globally standardized approaches to alt text creation, making it easier for developers and content creators to provide inclusive experiences.

The future of alt text is exciting, as it promises more efficient and user-centric approaches to web accessibility. As emerging technologies and trends continue to shape the digital landscape, alt text will remain at the forefront of ensuring a more inclusive and accessible online world for all users.

profile picture of authorLeonardo Dentzien


Ready to get started?

Make a free account, and find out how you and your team can change the way you write alt text, forever.