A quick overview of alternative text for images.
Images play a significant role in conveying information, evoking emotions, and enhancing the visual appeal of web content. However, for individuals who are blind or visually impaired, images are inaccessible without proper alternative text. Alternative text, also known as alt text, is a vital component of web accessibility that ensures everyone can access and understand the content, regardless of their abilities. In this comprehensive guide, we will delve into the importance of alternative text, explore various types of images and their appropriate alt text usage, provide good and bad examples, and offer a checklist for creating effective alt text.
Understanding Alternative Text
Alternative text is a textual description provided for an image that serves as a replacement when the image cannot be seen. It is primarily used by screen readers, assistive technologies used by individuals with visual impairments, to convey the meaning and context of images. Alternative text should be concise, descriptive, and convey the essential information or purpose of the image to ensure an inclusive browsing experience for all users.
Types of Images and Alt Text Usage
When it comes to alternative text, different types of images require different approaches. Let’s explore the various image types and their recommended alt text usage:
1. Meaningful Images
Meaningful images are those that provide relevant information or contribute to the understanding of the content. These images should have descriptive alt text that conveys the message they convey. Here’s an example of good alt text for a meaningful image:
Good Example: Alt text: “A group of diverse students engaged in a classroom discussion.”
2. Decorative Images:
Decorative images are those that don’t provide any meaningful information and are purely aesthetic or ornamental. These images should have empty alt text, using an empty attribute (“alt=””) or a null alt text (“alt=’null'”). This ensures that screen readers skip over them and focus on the relevant content. Here’s an example:
Good Example: Alt text: “” (empty alt text)
3. Functional Images:
Functional images are those that serve a specific function or convey important interactive elements. These images should have alt text that describes their purpose or functionality. Here’s an example:
Good Example: Alt text: “Submit button: Click to submit your form.”
4. Informative Images:
Informative images present complex data or information. The alt text for informative images should provide a concise summary of the content they convey. Here’s an example:
Good Example: Alt text: “Bar chart showing quarterly sales growth for 2021.”
5. Linked Images:
Linked images are images that act as links to other web pages or resources. The alt text for linked images should describe the purpose or destination of the link. Here’s an example:
Good Example: Alt text: “Read more: Explore the latest news and updates.”
Common Mistakes to Avoid
While creating alt text, it’s important to avoid common mistakes that can hinder accessibility. Here are some examples of bad alt text practices:
Bad Example 1: Alt text: “Image”
Bad Example 2: Alt text: “Picture of a group of people”
Bad Example 3: Alt text: “Click here”
In these bad examples, the alt text fails to provide any meaningful information about the image, making it inaccessible to individuals who rely on alternative text.
Creating Effective Alternative Text: A Checklist
Here is a checklist to help you create effective alternative text for images:
- Always include alt text for images.
- Make alt text concise and descriptive.
- Use appropriate alt text for different types of images (meaningful, decorative, functional, informative, and linked images).
- Avoid using the phrases “image of” or “picture of” in alt text.
- Use punctuation and capitalization to enhance readability.
- Don’t include unnecessary details or repeat nearby text in alt text.
- Ensure alt text is localized for multilingual websites.
- Test your website using a screen reader to ensure alt text is read correctly.
Alternative text is a critical aspect of web accessibility, allowing individuals with visual impairments to comprehend and navigate web content effectively. By understanding the various types of images and their appropriate alt text usage, and following best practices, you can create inclusive and accessible web experiences for all users. Implementing effective alternative text ensures that everyone, regardless of their abilities, can engage with and benefit from the valuable content your website has to offer.