What level is WCAG 1.3.4?

Level AA. It sits under guideline 1.3 Adaptable of the Perceivable principle.

What are common ways pages fail WCAG 1.3.4?

App locks into landscape and shows an "please rotate" overlay otherwise. Mobile site uses CSS to fight portrait orientation.

How do I fix WCAG 1.3.4 issues?

Build responsive layouts that work in both orientations. Only restrict orientation when interaction genuinely requires it (e.g. piano keyboard).

1.3 Adaptable · Perceivable

WCAG 1.3.4 Orientation

Level AA

Don't restrict content to a single display orientation (portrait or landscape) unless the orientation is essential — users with mounted devices may not be able to rotate.

Common failures

App locks into landscape and shows an "please rotate" overlay otherwise.
Mobile site uses CSS to fight portrait orientation.

How to fix

Build responsive layouts that work in both orientations.
Only restrict orientation when interaction genuinely requires it (e.g. piano keyboard).

Related criteria

WCAG 1.4.10 Reflow Level AA