By 2030, almost 20 percent of people in the United States will be over 65.  This is about the same number of people as who own an iPhone today – a very large and lucrative market.  But very few smartphone and tablet developers have experience designing apps for seniors.  It’s no secret that they spend much more time thinking about younger people.

But for those of you who see this as an opportunity, here are 10 tips when designing apps for seniors.  These are taken from our full Best Practices Guidelines for making technology senior-friendly.

Before getting into specifics it important to realize that when designing apps for seniors, it’s a big mistake to think in terms of “number of years.”  The diversity of this demographic group is stunning.  An 85-year-old may be more “able” than her 65-year-old neighbor.  Aging is a continuous process, but it is not linear or uniform.  We all get old differently.

Rather than years, it’s better to understand all the factors that impact seniors’ ability to use an app.  These include:

• Vision
• Hearing
• Movement control
• Memory
• Attention
• Decision making
• Learning
• Relationships, privacy and security
• Experience with technology
• Device bias
• Life stage and attitudes

Our complete Best Practices Guidelines are based on a careful review of over a hundred articles on how these factors can impact an older people’s use of technology.  From these we developed an expansive set of specific user interface design guidelines.  Below are the top 10 that we think are most important when designing apps for seniors:

1. Make user interface elements large enough so they are easy to target and hit. We recommend making touch targets 2.5cm wide or larger (average adult thumb), but never narrower than 1.6 cm wide (smaller adult index finger). The height should be no less than the width.  See our article on Understanding Recommended Target Sizes for more detailed information.
2. Include enough space between touch targets when designing apps for seniors. The smaller your targets, the more space you will need between them.  We recommend a minimum of 0.5 cm.  Minimize the possibility of unintentional finger taps near the edge of the user interface where various operating system functions might be unintentionally triggered.  Think carefully about these size and spacing considerations if your app will end up on devices with different screen sizes and resolutions.
3. Use large text. For body text, use a minimum font size of 14 points (0.19 inches).  For headings, use a minimum font size of 18 points (0.25 inches).  To eliminate the variations caused by screen pixel density, the specified minimums should be tested side by side with a  printed page where 1 point = 1/72 inch.  For smartphones which are likely to be held closer to the eye than a tablet you may be able to go 2 points (0.03 inches) smaller where needed.  Also, use sans serif fonts which seniors find easier to read and “scan” than other styles.  Use tools like the Sight Exclusion Estimator to test your app. See our article on Understanding Recommended Font Sizes for more detailed information.
4. Pay attention to brightness and contrast ratios between text (and images of text) and its background. We recommend a minimum contrast ratio of 7:1 between text and solid backgrounds.  The 7:1 level generally provides adequate compensation for the loss in contrast sensitivity experienced by older users with low vision who do not use assistive technology, and IT provides contrast enhancement for color blindness.  Using black and white will provide a contrast ration of 23:1.  But you can make exceptions for large text, inactive user interface elements, logos and decorations.  Avoid patterned backgrounds when designing apps for seniors.  These provide a lower contrast, and can also be distracting for older people.  Use tools like the Luminosity Colour Contrast Ratio Analyser to test your contrast ratios.   See our article on Understanding Recommended Color Contrast for more detailed information.
5. Use linear navigation structures and a minimum number of sub-menus when designing apps for seniors. The structure of the user interface should be as shallow as possible to minimize the number of finger gestures needed to navigate to a specific place or function.  Older users should be able to reach any part of the user interface with a maximum of two or three  finger gestures.  This is important in order to mitigate both cognitive impairments and movement control challenges.
6. Navigation elements should be visible at all times. Ensure that pathways for completing tasks are understandable.  Make the path for any given task a reasonable length (two or three gestures) and free of distractions and obstacles.  Avoid pop-up, slide-out and other hidden menus.  Provide an obvious mechanism that allows users to get back to their previous location or home when navigating user interface structure.  Use “home pages” and “back buttons” to make it easier to navigate to known reference points.  Use “bread-crumbs” where possible.  Whatever mechanism you use make sure it is consistent throughout the interface.
7. Maximize use of simple one-tap actions when designing apps for seniors. Where applicable, consider treating multiple finger taps as single.  In other words, if a person taps on a clickable user interface element more than once, accept the first tap and ignore the other taps.  Minimize the use of pinch, spread, multi-finger tap, and long press actions, particularly in interface elements that are likely to be used in sequence.  These are difficult for older people to execute and can cause physical strain.
8. Do not ask older people to remember material from one user interface screen to another. Avoid splitting tasks across multiple screens if they require memory of the content or actions on previous screens.  Reduce the number of information chunks that need to be kept in mind at any given time.  Try not to exceed five information chunks at one time when designing apps for seniors.  During longer user interface tasks, give clear feedback on status, progress and reminders of goals.
9. Make it easy to understand what each user interface component does when designing apps for seniors. Each distinct component should have only one function in any given user interface.  Use different colors, graphics and text for similarly shaped components (e.g., buttons) that have different functions, in order to help differentiate between the functions.  Supplement icons, buttons and other user interface elements with text labels that use terminology familiar to older people.  Make user interface items resemble their real-world counterparts as much as possible, for example, the home screen represented by a house icon.
10. Eliminate all user interface actions that require both good vision and high dexterity simultaneously. Ditto for both good vision and good hearing when designing apps for seniors.  Design your apps so that only one of these is needed; or better yet, where none of these is a requirement.  And take full advantage of the assistive and adaptive functions provided in iOS and Android software developer kits.  These will help you more easily address the physical impairments of aging when building apps across various devices.

You’ve probably noticed that most of these recommendations are good for any age group, not just the elderly.  But never lose sight of how especially important they are when designing apps for seniors.  Younger people are adaptable to poor user interfaces.   Older people are not.

Related Articles:  User Interface Best Practices Guidelines for Seniors | Top 10 NON-Technical User Interface Design Tips for Seniors