It is not possible to work with the Alt attribute on icons, so it is suggested to use an ARIA label or text with font size 0 to make the icons readable for a screen reader. I forward the translated suggestion below:
Error description: The icon has no visually visible text and has no text alternative.
Measure: Decorative icon fonts (contain no information even for sighted people, e.g. snowflakes, balloons) must be hidden from screen reader users using a suitable technique (e.g. ARIA-hidden=”true). Information-carrying icons without visually visible labels (e.g. printer symbol ) must provide a text alternative. It is not possible to store a text alternative using the alt attribute. Instead, this must be hidden using a suitable method, for example by using the ARIA label :none” should not be used as this cannot be read by all screen readers. The text alternative must be described in the main language of the page. However, information-bearing icons with visually visible labels do not require a text alternative. For example, a printer symbol with the text “Print” next to it.
