Alt text (alternative text), also known as alt tags, is a written description of an image that is displayed if the image cannot be loaded for some reason or if the user is visually impaired and using a screen reader. The alt text provides a brief description of the content and context of the image, allowing visually impaired users to understand the content of the image and providing search engines with information about the image for better indexing and ranking.

The importance of alt text for visually impaired users cannot be overstated. Screen readers rely on alt text to describe images to users, and without it, the images are simply unreadable to these users. This can result in a frustrating and confusing experience, as they are unable to understand the content of the page they are viewing. Alt text helps ensure that all users, regardless of ability, have equal access to the content on a page.

In addition to being important for accessibility, alt text is also important for search engines. Search engines use alt text to understand the content of images and to determine their relevance to a search query. This is particularly important for image-rich websites, such as e-commerce sites, where images play a significant role in the user experience and in search rankings.

When writing alt text, it’s important to be descriptive, yet concise. A good rule of thumb is to keep alt text under 125 characters. The text should accurately describe the content and context of the image, including any relevant details such as color, shape, and size. Avoid using phrases like “image of” or “picture of,” as they are redundant and do not add any value to the description.

It’s also important to avoid using alt text that is irrelevant, misleading, or overly verbose. Search engines may penalize websites that use irrelevant or misleading alt text, as it can harm the user experience and search rankings. Additionally, using overly verbose alt text can result in the alt text being truncated, making it less useful for both visually impaired users and search engines.

In conclusion, alt text is an essential aspect of web design and development that provides visually impaired users with a description of the content and context of an image, and helps search engines better understand the content of a page. When writing alt text, keep it descriptive, yet concise, and avoid using irrelevant or misleading text. By doing so, you can help ensure that all users have equal access to your content and that your website is well-indexed by search engines.