How do you write clear and descriptive alt text for your images and videos?

1 Why alt text matters

Alt text is not only a legal requirement for web accessibility, but also a way to enhance the user experience and the SEO performance of your website. Alt text helps users with visual impairments, low bandwidth, or incompatible devices to understand the meaning and context of your images and videos. It also helps search engines to index and rank your website based on the relevance and quality of your content. Without alt text, you risk losing potential customers, visitors, and conversions.

2 How to write alt text

Writing alt text is not a one-size-fits-all task - it depends on the purpose, function, and content of your images and videos. To ensure effective alt text, be concise and accurate with simple and clear language to describe the essential information. Be specific and relevant by providing enough context and detail to convey the message and function. Additionally, be informative and descriptive by using keywords and phrases that match the query and intent of your users. Avoid using the file name, the word "image" or "video", or the format of your images and videos as alt text.

3 How to test alt text

Testing alt text is an important part of web testing, as it can uncover errors, gaps, or inconsistencies in your content. Depending on your tools and goals, there are various approaches to testing alt text. For example, you can use a screen reader or browser extension to listen to how the alt text sounds to users with visual impairments and ensure it is clear and relevant. Additionally, a web accessibility checker or validator can be used to scan for missing, broken, or incorrect alt text and verify it complies with web accessibility standards. Lastly, a SEO tool or search engine can be used to analyze how the alt text affects the ranking and visibility of your website, making sure it contains keywords that match user queries and intent.

4 How to improve alt text

Improving alt text is an ongoing process that requires regular updates, reviews, and feedback. To ensure the best results, you should use different alt text for different images and videos, even if they look similar or have the same function. You should also use captions, titles, or labels to complement your alt text for complex or informative images and videos. Additionally, you should use null alt text for decorative or background images and videos that do not add any value or information to your website. This will help you avoid using duplicate or redundant alt text, as well as empty or blank alt text that can create gaps or errors in your content.

5 How to learn more about alt text

Gaining knowledge about alt text can help you become more proficient in web testing and increase the quality of your website. To learn more about alt text, you can explore resources and examples from the Web Content Accessibility Guidelines (WCAG) for technical specifications and techniques, the W3C Web Accessibility Initiative (WAI) for tutorials, tips, and examples for different types of images and videos, and the Moz Blog for articles, guides, and tools for SEO purposes.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?