What the standard says
Content does not restrict its view and operation to a single display orientation, such as portrait or landscape, unless a specific display orientation is essential.
Why it matters
Many people have their device fixed in one orientation on a mount. Forcing portrait means they have to turn their whole chair.
What a failure looks like
- failsA CSS or app-level lock to portrait.
How to fix it
- doSupport both orientations unless the orientation is essential — a piano keyboard, say.
How A11ySignal checks it
1 automated check runs against this criterion on every scan.
seriouscss-orientation-lockCSS Media queries must not lock display orientation