WCAG 2.1 – Criterion 3.3.6 – Error prevention (all) (Level AAA)

Today, as part of the WCAG Academy, we’re covering criterion 3.3.6 – Error prevention (all) (Level AAA) – related to a criterion we’ve already discussed at Level AA. You can think of it as its “child”.

So, what’s the difference, and why has W3C given us another criterion?

In short – while the Level AA criterion requires us, as content creators, to ensure that users don’t make mistakes, such as by adding a confirmation message, WCAG 3.3.6 narrows this down to preventing form errors.

WCAG 3.3.6 Error prevention (all)

Criterion 3.3.6 helps us ensure that the data entered in forms is correct. As website or mobile app creators, we need to ensure that the data entered by users is verified, that the form isn’t accidentally submitted empty (like by accidentally pressing a button), and that users can correct or change their data after submission.

What can we do?

• Implement proper validation that checks both the type of data and its presence;
• Add suggestions for fixing errors that allow users to correct mistakes;
• Provide an option to edit the data after submission (e.g., an “Edit” button in an address form);
• Include an additional confirmation message – “Are you sure (…)?” using, for example, a modal window.

As you can see, Level AAA criteria are often very similar to their “parent” criteria. Even the techniques listed by W3C usually refer to the older criterion. That’s why it’s important to know all of them and interpret them correctly. You can check it out in the w3c article.