Can user-side adaptations be sufficient for passing some WCAG 3 requirements?

[alastc]

An obvious example of this question is: If the user can increase the contrast of text, do we need to set a minimum contrast level for the authored presentation?

Another customization that comes to mind is prefers-reduced-motion: Can we allow digital products to go wild with animation (and even flashing), so long as there is a preference for users that turns it off?

The above statements are a simplification though, particularly for "the user can...".

• Do all users (or some level of "enough" users) have that customization available?
• Do all users (or some level of "enough" users) know that they have that customization available?
• If that customization is widely available (e.g. present in a particular browser), but not ubiquitous, should it be the users' responsibility to use that browser? (The answer is yes for a screenreader, but this doesn't feel quite the same.)

Consider also the impact on testing, this issue against WCAG2 highlights the variety of conditions a web page can have.

We have a concept of accessibility supported, and accessibility-support-sets that will help, but it feels like we need a fairly general answer to this question.

I'm not suggesting that we remove requirements, but that if your accessibility support set supports a particular customization, that could be relied on when making a claim that you pass. E.g. a method is "Using prefers-reduced-motion to prevent flashing". Should that be enough? Does it matter that it's for flashing compared to contrast?

[mraccess77]

I worry about statements that say the user can apply their own styles. Users could write their own JavaScript to add things into the focus order that weren't - where do we draw the line? Minimum contrast is just that a minimum that benefits many people and is needed for people with contrast limitations. Certainly, anything beyond a minimum is different - but requiring every user be able to write CSS or to force anyone who just wants a minimum level of contrast into a high contrast theme (which can be worse for some) is not always helpful.

[WayneEDick]

There is another glitch in this on the fly accommodation. It is inconsistent. One browser will provide a useful feature and another provides a different feature. The two together is the best fit but the user must flip flop Missing the best access. I think this issue is too granular to be an accessibility issue. A document should be accessible in both. Best Wayne

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On Fri, Feb 6, 2026 at 4:46 PM Jonathan Avila ***@***.***> wrote: I worry about statements that say the user can apply their own styles. Users could write their own JavaScript to add things into the focus order that weren't - where do we draw the line? Minimum contrast is just that a minimum that benefits many people and is needed for people with contrast limitations. Certainly, anything beyond a minimum is different - but requiring every user be able to write CSS or to force anyone who just wants a minimum level of contrast into a high contrast theme (which can be worse for some) is not always helpful. — Reply to this email directly, view it on GitHub <#556 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AB6Q4F66KC7Y4U22I3BROG34KUYVHAVCNFSM6AAAAACUHHQAQGVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTKNZSGM2TMMA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>