在某些情况下，对于html img标签，alt =“”是否合适？

Question

We have a project that is all about web accessibility compliance. About a week from launch we have the accessibility committee reviewing our site to give the final thumbs up. However, they reported back to us that we should set alt="" on some of our icons because they do not provide any additional content to the site and thus are merely distracting to a screen reader but yield no benefit.

1. Is this correct?
2. I was under the impression alt was a required attribute of img? Sure alt="" on an img tag would include the alt attribute but is this valid ?

Comments are appreciated.

Answer 1

If the icons provide any functionality (user-clickable or something), I'd recommend setting a descriptive alt value. If they are just decorative, then alt="" is valid.

From the standard :

While alternate text may be very helpful, it must be handled with care. Authors should observe the following guidelines:

• Do not specify irrelevant alternate text when including images intended to format a page, for instance, alt="red ball" would be inappropriate for an image that adds a red ball for decorating a heading or paragraph. In such cases, the alternate text should be the empty string (""). Authors are in any case advised to avoid using images to format pages; style sheets should be used instead.
• Do not specify meaningless alternate text (eg, "dummy text"). Not only will this frustrate users, it will slow down user agents that must convert text to speech or braille output.

Answer 2

根据这个来源： http ： //msdn.microsoft.com/en-us/library/ms228004（ v = VS.100） .aspx＃ guideline_11__providing_alternate_text_for_images省略alt属性会使一些屏幕阅读器发出文件名并分散用户的注意力，这就是建议将alt设置为空字符串的原因。

Answer 3

The alt attribute is always required if you want your code to pass validation, however it's not necessary for the alt attribute to have a value.

If you're using images for page decoration (for example, rounded corners or shadows for browsers that don't support CSS3), these images should be in the CSS rather than inside <img> tags in the html. However, there are cases when you may have images that should be included as actual images in the html, even though there is no meaningful way to describe them for screen reading software. In this case, w3.org says that it's okay to use alt="" . 1

1: http://www.w3.org/QA/Tips/altAttribute