The Importance of Text Alternatives in Web Accessibility
In the past 20 or so years, the web has become an integral part of how we access information, communicate, and engage with the world. However, not everyone experiences websites or apps in the same way. People with disabilities — whether visual, auditory, cognitive, or motor-related — encounter unique challenges when interacting with digital content. That's where accessibility comes in, ensuring that content is perceivable, operable, understandable, and robust (the four principles of the Web Content Accessibility Guidelines, or WCAG).
One of the most crucial elements of accessibility is perceivable content, which ensures that all users can perceive the information and interface, regardless of the tools they use or the limitations they may have. A key feature of perceivable content is the use of text alternatives — descriptions provided for non-text elements like images, videos, or buttons. These alternatives ensure that the content remains accessible to everyone, including those who rely on screen readers or other assistive technologies.
What Are Text Alternatives?
Text alternatives, often referred to as "alt text," are short descriptions added to images, icons, buttons, and other non-text content on a webpage. They allow users with visual impairments to understand the content through text that can be read by screen readers or translated into Braille. Alt text is one of the fundamental requirements for ensuring websites are accessible and compliant with guidelines like WCAG.
Here’s an example of how text alternatives work:
Imagine a website features an image of a chart showing sales growth. For sighted users, the chart visually conveys important information. For a user with a visual impairment, a screen reader can describe the chart's alt text, such as: "Line chart showing sales growth from 2020 to 2023, with a 50% increase in the final year." This ensures that the user gains the same essential information as a sighted individual.
Why Is Perceivable Content Necessary?
Perceivable content is crucial because it ensures that no user is excluded from accessing information. When content is inaccessible, it creates barriers that can limit a person's ability to engage, learn, or participate fully. For example, a visually impaired person may miss important context if images don’t have alt text. Similarly, someone who is deaf might struggle with video content if it doesn’t include captions or a transcript.
For many people with disabilities, assistive technologies like screen readers are essential tools. Screen readers can only interpret text content, which means that any non-text content (like images, buttons, or complex charts) needs a text alternative to ensure it can be understood. Without these alternatives, essential parts of a webpage might remain hidden or indecipherable to those users.
Moreover, accessibility doesn’t only benefit individuals with disabilities; it often enhances usability for all users. For instance, providing alt text not only helps people who rely on screen readers but also assists users in low-bandwidth environments where images may not load. Similarly, including captions in videos benefits those in noisy or quiet environments where they cannot use sound.
Best Practices for Creating Effective Text Alternatives
Writing effective text alternatives requires careful attention to the context and purpose of the content. Here are some key best practices:
Be Descriptive but Concise
The alt text should convey the essential information in the image or content without being overly verbose. For example, for an image of a dog, "Golden retriever playing with a ball in the park" is more useful than just "dog."
Context Matters
Tailor the alt text to the image's role on the page. If the image serves a decorative purpose, such as a background image, it may not need an alt text, or you can use an empty alt attribute (alt=""). However, if the image provides critical information, the alt text should reflect that.
Avoid Redundancy
If the same information is conveyed elsewhere on the page (e.g., in a caption), there’s no need to repeat it in the alt text.
Functionality
For buttons and interactive elements, alt text should describe the action, not just the object. For example, instead of "magnifying glass," the alt text for a search button should say "Search."
Conclusion
Text alternatives play a pivotal role in making digital content perceivable for all users, particularly those with visual impairments who rely on assistive technologies like screen readers. By providing thoughtful and descriptive alt text for non-text elements, websites and apps ensure they are accessible, inclusive, and usable by everyone. Not only is this good practice, but it also aligns with the ethical and legal responsibility to make digital spaces accessible to all. By embracing accessibility through perceivable content, we can create a more equitable web for everyone.
