Why are there now divergent requirements?
The HTML conformance requirement takes into account the accessibility and usability needs of users:
- They have a very slow connection and are browsing with images disabled.
- They have a vision impairment and use text to speech software.
- They have a cognitive impairment and use text to speech software.
- They are using a text-only browser.
- They are listening to the page being read out by a voice Web browser.
- They have images disabled to save on download costs.
- They have problems loading images or the source of an image is wrong.
- 220.127.116.11 Requirements for providing text to act as an alternative for images
- ARIA10: Using aria-labelledby to provide a text alternative for non-text content
- F65: Failure of Success Criterion 1.1.1 due to omitting the alt attribute or text alternative on img elements, area elements, and input elements of type “image”
- Is the Alt Attribute Dead?
- Is the Alt Attribute Dead? – Article on Updated F65 – WAI email thread