We are designing a B2B e-commerce site and the client is requiring AAA compliance. I know, I know.. but here we are. I have searched and cannot find anything regarding scrollbars for AAA compliance. Are they allowed?

These would be used on left side of page for product facets. There can be dozens or even hundreds of facets and to show them all inline would be a lot... We are already dealing with having the checkboxes being 44px and I imagine if allowed, the scroll bar would also have to be that wide.

Any comments? thoughts? alternative ideas?


  • Usually the standard excludes platform-generated UI elements from the conformance, and scrollbars would fall under that.
    – Andy
    Dec 7, 2022 at 16:41

1 Answer 1


Hopefully the client is asking for AA conformance and not AAA conformance. The W3C says that full AAA conformance is not possible.

It is not recommended that Level AAA conformance be required as a general policy for entire sites because it is not possible to satisfy all Level AAA Success Criteria for some content.

There are some great AAA guidelines, such as 2.4.9 ink Purpose (Link Only) and 1.4.6 Contrast (Enhanced), but your client should be focusing on AA conformance which is the standard required by most country laws.

That being said, the only guideline that talks about scrollbars is 1.4.10 Reflow. It mainly says the user should not be forced to scroll in two directions (ie, both a vertical and a horizontal scrollbar) "Except for parts of the content which require two-dimensional layout for usage or meaning".

That last phrase is a bit subjective. The guideline gives a few examples of content that might require scrolling in two directions, such as maps and tables, but it's sort of up to you to decide if you need scrollbars in both directions.

Regarding target size, there is a AAA guideline that says 44x44 is the minimum size, 2.5.5 Target Size, but it also has a list of exceptions so you don't necessarily need that size of checkbox if you can fit into one of the exceptions.

When WCAG 2.2 comes out, there is a new AA guideline that says 24x24 is the minimum size. As mentioned, most companies shoot for AA conformance. Currently, WCAG 2.1 AA does not require a minimum target size so companies often don't focus on that. That will change when WCAG 2.2 comes out. However, if a company chose to follow the WCAG 2.1 AAA guideline of a 44x44 target size, then they'll automatically conform to the new 24x24 requirement.

  • Thank you for the reply, they are asking for AAA and we've discussed why they shouldn't and we understand we can't really deliver AAA without them updating content etc. My guess is we'll end up at a "AA+". Whatever we can make AAA we will. We are redesigning the checkboxes in a way that their target size is large enough and we don't have to have visually huge checkboxes. I think based on the reflow requirements you linked to - I think we should be ok with scrolling facets, especially since each group of facets has a search/filter box above it that needs to be visible. Thank you! Dec 6, 2022 at 18:28
  • Great answer. I would add the following quote, maybe, on target size for the scrollbar: “Except when […] User Agent Control: The size of the target is determined by the user agent and is not modified by the author;”
    – Andy
    Dec 7, 2022 at 16:43

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