Alt text, or alternative text, is a critical component in web accessibility, enabling screen readers to describe images for visually impaired users. However, not every image on a website needs alt text. There are specific instances when leaving alt text empty is the recommended approach. Understanding when to leave alt text empty can improve the overall user experience and reduce unnecessary distractions for users relying on assistive technologies.
What is Alt Text?
Alt text is a brief description of an image, embedded in the HTML code, that allows screen readers to convey the content of the image to users with visual impairments. While alt text is essential for images that convey important information, some images serve purely decorative purposes and do not contribute meaningfully to the content of a page. These are the cases where leaving the alt text empty is not only acceptable but also beneficial.
The Purpose of Leaving Alt Text Empty
Leaving alt text empty is done using a “null” tag, which looks like this in HTML: alt=” “. This tag tells assistive technologies that the image is purely decorative and should be ignored. When used correctly, empty alt text prevents the screen reader from announcing irrelevant or redundant content to users, improving both the flow of information and the user experience.
When to Leave Alt Text Empty
1. Decorative Images
Decorative images do not contribute to the understanding of the page’s content. Examples of decorative images include background images, design elements like borders, icons that are used purely for aesthetics, and other visuals that don’t provide context or meaning to the surrounding content. In these cases, leaving the alt text empty allows screen readers to skip over the image entirely.
2. Icons with Descriptive Text Nearby
Sometimes, icons are used alongside visible text that already provides the necessary information. For instance, if an icon of a phone is next to the word “Contact Us,” there is no need for alt text describing the icon. The text next to it already conveys the intended message, making the alt text redundant. In such scenarios, leaving the alt text empty ensures that users aren’t subjected to repetitive or unnecessary information.
3. Images Used for Spacing or Formatting
Web designers often use transparent images or small, simple graphics to adjust the layout or spacing on a webpage. These images do not contain any meaningful content and are solely used for design purposes. Providing alt text for these images would only clutter the screen reader output with irrelevant information. In such cases, leaving the alt text empty is the preferred approach.
Why You Should Leave Alt Text Empty for Decorative Images
1. Avoid Audible Clutter
If you provide alt text for every image on a page, including decorative ones, it can lead to “audible clutter” for screen reader users. This means that users will have to listen to unnecessary descriptions of decorative images, which do not add any value. By leaving the alt text empty for these images, you help users focus on the content that matters.
2. Prevent User Distraction
Decorative images with alt text can distract users from the main content of the page. For example, if there is an unrelated image with alt text in the middle of an article, a screen reader may interrupt the flow of the article to announce it. This can confuse and frustrate users. Leaving the alt text empty prevents such distractions.
3. Optimize Screen Reader Efficiency
The goal of web accessibility is to ensure a smooth, logical experience for users with disabilities. When screen readers encounter empty alt text, they skip over the image entirely, allowing users to focus on important content without being interrupted by non-essential information. This makes the browsing experience more efficient and user-friendly.
When You Should Not Leave Alt Text Empty
While there are clear reasons for leaving alt text empty, it’s important to know when to include descriptive alt text. Any image that adds meaning, provides information or contributes to the understanding of the content on the page should have appropriate alt text. Examples include:
- Informative Diagrams or Charts: If an image conveys specific information that is not available elsewhere on the page, alt text is essential for accessibility.
- Product Photos: When selling a product online, including descriptive alt text ensures that visually impaired users can understand the product being presented.
- Content Illustrations: If an image is used to enhance or clarify the written content (e.g., a photo accompanying an article), the alt text should describe the image’s relevance to the topic.
How to Determine if Alt Text is Needed
A simple way to decide whether or not to include alt text is to ask yourself the following questions:
- Does the image provide important information? If yes, include alt text.
- Would the page lose meaning without the image? If yes, add descriptive alt text.
- Is the image purely decorative? If yes, leave the alt text empty.
By following these guidelines, you ensure that your content is both accessible and user-friendly, while also avoiding the pitfalls of overloading screen reader users with unnecessary information.
Conclusion
Understanding when to leave alt text empty is essential for creating an accessible and efficient website experience. Decorative images, icons with accompanying text, and images used for formatting or spacing should all have empty alt text to avoid cluttering screen readers with unnecessary details. At the same time, meaningful images that contribute to the content should always include descriptive alt text. By using alt text thoughtfully and appropriately, you can significantly enhance the accessibility of your website, making it more inclusive for all users.