Copy, images, audio, and video supply the information that people want from your app. You can help make your content accessible to everyone by striving for simplicity of expression and providing alternative versions of the information.
Copy and Images
Edit copy so that it is simple and clear. When copy is straightforward, uncomplicated, and free of errors, all users benefit.
Provide alternative descriptions for all images that convey meaning. If you don't describe the meaningful images in your content, you prevent VoiceOver users from fully experiencing your app. To create a useful description, start by reporting what would be self-explanatory to someone who is able to see the image. Because VoiceOver reads the text surrounding the image and any captions, focus your description on information that's conveyed by the image itself.
Make infographics fully accessible. Provide a concise description of the infographic that explains what it conveys. If people can interact with the infographic to get more or different information, you need to make these interactions available to VoiceOver users, too. The accessibility APIs provide ways to represent custom interactive elements so that assistive technologies can help people use them. For developer guidance, see UIKit Accessibility and AppKit Accessibility.
Hide purely decorative images from assistive technologies. Making VoiceOver describe a purely decorative image can waste time for users and add to their cognitive load without providing any benefit.
Give each screen a unique title and provide headings that identify sections in your information hierarchy. When people arrive on a screen, the title is the first piece of information they receive from an assistive technology. To help people understand the structure of your app, create a unique title for each screen that succinctly describes its contents or purpose. Similarly, people need accurate section headings to help them build a mental map of the information hierarchy of each screen.
Audio and Video
Provide closed captions. Closed captions give people a textual equivalent for the audible information in a video. Using closed captions lets you provide multiple translations for the same content and allows the system to choose the version that matches the user’s settings. Because closed captions aren't always available, it's important to provide subtitles, too. For developer guidance, see Adding Subtitles and Alternative Audio Tracks.
Supply audio descriptions. Use audio descriptions to provide a spoken narration of important information that is presented only visually.
Consider providing transcripts. It can be a good idea to provide a complete textual description of a video, covering both audible and visual information, so that people can enjoy the video in different ways.