Alt tags, more accurately called "alt attributes", are used within an HTML code to describe the appearance and function of an image on a webpage. Technically, not all images require alt tags. However, you should use alt tags for images in most cases due to several important reasons:
Accessibility: The alt attribute provides a textual description of an image for those with visual impairments using screen readers.
SEO Benefits: Although the direct impact of alt tags on SEO is debated, they can help search engine crawlers better understand the image content, which might lead to improved indexing and potentially better visibility in image search results.
Missing Image Fallback: If an image fails to load, the text in the alt tag will display in its place, providing context to the user about what should be there.
There are some exceptions where alt attributes might not be necessary or where an empty alt attribute (i.e.,
alt="") would suffice. These include decorative images that don't contribute to the content or information value of the page, or images that are described sufficiently by surrounding text content.
Here's an example of how to add an alt attribute to an image in HTML:
If the image is purely decorative and doesn't add to the content's meaning, an empty alt attribute can be used, like so:
However, as a best practice, strive to provide meaningful alt texts whenever possible to improve the user experience and accessibility of your web content.