HTML Checking for Large Sites
Rocket Validator automatically scans your sites for accessibility issues using the W3C Validator,
hosted on our own servers and integrated into our web crawler.
An “img” element must have an “alt” attribute, except under certain conditions. For details, consult guidance on providing text alternatives for images.
<img> tags, used to include images on a document, require an alt attribute to describe the contents of the image. This is essential for users that cannot see the image (like screen reader users), or as an alternate text when the image cannot be displayed. Example:
<img src="photo.jpg" alt="Person holding a cat" />Related W3C validator issues
- Bad value “” for attribute “src” on element “img”: Must be non-empty.
- Bad value “X” for attribute “src” on element “img”: Illegal character in path segment: space is not allowed.
- Bad value “X” for attribute “src” on element “img”: Illegal character in scheme data: space is not allowed.
- Bad value “X%” for attribute “width” on element “img”: Expected a digit but saw “%” instead.
- Element “img” is missing required attribute “src”.
- The “border” attribute is obsolete. Consider specifying “img { border: 0; }” in CSS instead.
- When the “srcset” attribute has any image candidate string with a width descriptor, the “sizes” attribute must also be present.