Many mobile apps allow users to operate controls with motion in some way. For example, the user might be able to shake their device to refresh content, or they might tilt their device to move to the next page in a process.
When implemented correctly, motion controls can improve accessibility and enhance the user experience for a wide variety of people.
There’s just one problem: Motion controls can also harm accessibility, particularly when the user has no alternative. Some people may be unable to shake their devices; some users may have smartphones with broken gyroscopes. Ideally, you’ll want your app to work for as many people as possible (and provide every user with an equivalent experience).
Motion controls must be optional to be accessible
We’re not trying to discourage developers from using motion controls; some users really appreciate the option, provided that it’s — well, an option.
The Web Content Accessibility Guidelines (WCAG) directly addresses motion controls in Success Criterion (SC) 2.5.4, “Motion Actuation:”
Functionality that can be operated by device motion or user motion can also be operated by user interface components and responding to the motion can be disabled to prevent accidental actuation.
This criterion has limited exceptions for motions that are used to operate functionality through an accessibility-supported interface, as well as motions that are essential.
For example, if you’ve developed a sky mapping app that uses the smartphone’s gyroscope and GPS to tell users the name of each planet in the night sky, the motion controls might qualify as “essential.”
But in most cases, motion controls aren’t truly essential — and you have a strong incentive to provide users with as many interface options as possible.
Remember, not all smartphones have flawless motion controls (and some app users don’t even use smartphones). If people can’t use their app with different types of technologies, you’ve limited the potential size of your audience.
For additional guidance, read: Understanding WCAG Exceptions for Essential Functionality
Keep motion controls simple, and don’t hide alternative controls
To implement motion actuation in an accessible way, think about the experiences of real-life users. That includes people with disabilities that affect their mobility, cognition, and sensory perception, along with people with temporary or situational disabilities (such as a broken phone gyroscope).
Some tips to keep in mind:
- Motion controls should be simple and intuitive. Shaking a device is intuitive — moving the device in a figure-eight pattern is less intuitive.
- Provide users with clear instructions for using the motion controls.
- Provide an option for disabling the motion controls. Make sure the option is clearly labeled, and where possible, provide it in a clearly visible location (don’t make the user dig through menus to find the motion actuation setting).
- Make sure your app fully supports keyboard-only operation. Keyboard accessibility is crucial for inclusive design, but unfortunately, mobile developers often overlook keyboard-only users.
- If motion controls trigger animations, make sure those animations meet WCAG’s requirements. For additional guidance, read: 4 Quick Ways to Check Web Animations for Accessibility.
As you design your app, think about how each feature will impact users with disabilities. Create user experience (UX) personas with disabilities and test your product against WCAG’s Level A/AA success criteria throughout development.
Remember, digital accessibility doesn’t limit your creativity
Prioritizing accessibility won’t force your team to create a bland, featureless app. The best practices of accessibility support the best practices of coding, design, and development — you’ll build a robust product that works for every type of user.
However, you’ll need to make a commitment: If you ignore accessibility during the first stages of development, your accessibility debt will grow. That means more time spent on remediations, redesigns, and updates.
If you’re ready to build better content, the Bureau of Internet Accessibility is ready to help. We provide accessibility testing, training, and free resources to help developers create (and maintain) an accessible mindset. Learn more by talking with us or download our free mobile accessibility checklist.