What is a focus trap in modal dialogs and how do you prevent it?

• A. A focus loop within the modal; prevent by returning focus to the trigger on close and removing tab focus when the modal closes.
• B. A lock on the page header preventing navigation while the modal is open.
• C. A feature that prevents the background from scrolling.
• D. A method to automatically move focus to the last element opened.

Answer: (A)

A focus trap means keeping keyboard focus inside the modal while it’s open, creating a loop of focusable elements within the dialog so the user can’t tab to elements behind it. To prevent this, manage focus so it never escapes the modal while it’s open: trap Tab and Shift+Tab inside the modal so focus cycles among the modal’s controls, and when the modal closes, restore focus to the element that opened it. This restoration is crucial because it returns the user to a predictable place in the page flow. In practice, you’d also set the initial focus to the first focusable item in the modal when it opens and re-enable normal page focus afterward, ensuring accessibility for keyboard users and screen readers. The other options describe scrolling behavior or page-wide locks, which don’t address keeping the user’s focus constrained to the dialog.