You’ve most likely come across websites that aren’t mobile compatible. You’d like to read a page in portrait mode, but the page’s set default is landscape, so you have to navigate back forth in order to read an entire line of text. Super annoying, right? For a person with certain physical or sensory disabilities, compatibility with modern tablet and phone technology can mean the difference between being able to read your amazing blog post about rare cheeses and being left to fend for themselves in the unforgiving wilderness of store-brand Cheddar Jack.
Smartphones, tablets, and other devices that can dynamically adjust default display orientation are often hindered if a page’s display orientation is restricted. This is especially impactful for users with certain disabilities or limitations; for instance, if someone in a wheelchair keeps their device mounted on their chair’s arm in a fixed position, or if a user experiencing low vision wishes to increase the size of the text on a page by displaying it in landscape.
Content on your site or app should not limit its operation and view to just one display orientation, such as landscape or portrait, unless a certain display is crucial to understanding or using the site or app. Situations in which a specific display orientation would be needed can include:
Please note that many devices allow users to lock their display orientation. This rule doesn’t apply to that side of the equation. You only need to worry about whether the orientation is restricted from the content author’s side of things. If your site or application’s orientation is not restricted, then it should adjust accordingly to a user’s locked display.