3.2.1

3.2.1 On Focus

WCAG says:

When any user interface component receives focus, it does not initiate a change of context.

When this is applicable

When there are interactive elements (links, form elements or other interactive objects).

Check there are no changes of context

Tab through everything and click on everything you wouldn't expect to initiate a change of context, such as a form field.

Check:

• there is no change of context - for example, a new window opens, a form gets submitted, focus gets moved elsewhere, the viewport changes
• content doesn't change in a way that also changes the meaning of the page

Sometimes an automated script can trigger a change of context. If such a script coincides with an element getting focus, double check it was not the focus which caused that change of context. For example, if a modal window appears asking you to sign up for a newsletter, it's likely this was not the result of focusing on an element.

Best practice

When a page loads, no other window, tab or modal window (that receives focus) should open.

Mobile app testing

Use an external keyboard.