Rule - MD045

Property	Value
Aliases	md045, no-alt-text
Autofix Available	No
Enabled By Default	Yes

Summary

Images should have alternate text (alt text).

Reasoning

Accessibility

All four types of the Image Markdown element transfer the text in the label text part of the element into the img tag's alt parameter. That parameter is used by screen readers to render an audio description of that image to sight impaired people.

Examples

Failure Scenarios

This rule triggers when the link label for an image has no characters or only whitespace characters. As the focus of this rule is to provide text to help identify the image, the whitespace characters compared against are the set of Unicode whitespace characters.

````Markdown

![][link]

[link]: /url "a title"``` ````

Note that for the shortcut and collapsed types of image links, it is impossible to create an example that triggers this rule. For more information, consult the GitHub Flavored Markdown specification.

Correct Scenarios

This rule does not trigger if the link label for an image has at least one non-whitespace character:

Markdown ![link](/url)

Fix Description

The reason for not being able to auto-fix this rule is context. While it is easy to detect that no alternate text has been provided for an image, the summation of the indented content of the link exceeds the scope of the project's context. Basically, any generated context would require scanning the destination link and providing a summary of that image that was relevant to the current document.

Configuration

Prefixes
plugins.md045.
plugins.no-alt-text.

Value Name	Type	Default	Description
enabled	boolean	True	Whether the Rule Plugin is enabled.

Origination of Rule

This rule is largely inspired by the MarkdownLint rule MD045.