Rocket Validator looks for accesibility violations on your pages using the axe-core accessibility engine, hosted on our own servers and integrated into our web crawler. You don't need to buy an additional license, everything's already included in your Pro account at Rocket Validator.
WCAG: Best Practice: Hidden content on the page cannot be analyzed
Informs users about hidden content that cannot be analyzed for accessibility violations.
Hidden content cannot be automatically analyzed for accessibility rule violations.
Visually hidden content must be accessible by both sighted and screen reader users. If there is a compelling reason to hide content from sighted users, there is usually a compelling reason also to hide that content from blind users. When the content is made available to sighted users, it makes sense to make it available to blind users as well.
Content will be hidden from screen reader users (and all sighted users too) when the CSS properties
visibility: hiddenare used. Changing CSS properties to
display: inline, or using other display values makes the items available to screen reader users.