How to Use Alt Text for Decorative and Functional Images
Alt text, or alternative text, is crucial for accessibility and SEO. It helps users, especially those utilizing screen readers, understand the context of images on a webpage. However, the approach to writing alt text differs for decorative and functional images.
Understanding Decorative Images
Decorative images are those that do not add significant content to the page. Examples include background images, patterns, and purely aesthetic visuals. Since these images don't convey information, they should be marked in a way that indicates their decorative nature.
For decorative images, the best practice is to use an empty alt attribute: alt="". This tells screen readers to skip the image, allowing users to focus on content that matters. Overloading screen readers with unnecessary descriptions can lead to a frustrating user experience.
Crafting Alt Text for Functional Images
Functional images serve a purpose, such as conveying information or enhancing user interaction. Typical examples include infographics, buttons, charts, and product images. For these, informative alt text is essential.
When writing alt text for functional images, consider the following guidelines:
- Be Descriptive: Clearly describe the image's content and purpose. For instance, instead of saying "dog," specify "golden retriever playing fetch."
- Keep It Concise: Aim for 125 characters or fewer. This ensures that the information is easy to grasp quickly.
- Use Relevant Keywords: Incorporate SEO keywords where appropriate, but avoid keyword stuffing. A well-placed keyword can enhance search engine visibility.
- Explain Context: Provide context to aid understanding. For example, "bar chart showing the sales growth of product X in Q1 2023."
Examples of Effective Alt Text
Here are some examples to illustrate how to effectively write alt text for both decorative and functional images:
- Decorative Image:
alt=""for a background pattern on a website. - Functional Image:
alt="Woman in a blue jacket examining the product features on an electronic device."for a product shot.
Conclusion
In summary, using alt text effectively requires awareness of the image's function. For decorative images, using an empty alt attribute helps maintain the flow of content for assistive technologies. For functional images, descriptive, concise, and context-aware alt text enriches user experience and optimizes SEO. Implementing these practices not only makes your website more accessible but also improves its performance in search engine rankings.