Mobile CTA (Call-To-Action) buttons present unique issues for UI and UX Design. Since CTA buttons generally are those features and actions you want the user to easily recognize and interact with, the characteristics that allow for that to happen need to be easily transferable across different platforms and devices. Certain elements need to be considered when designing effective actionable buttons for mobile UIs.
The most recognizable button shape is the square/rectangle, sometimes with rounded corners depending on the visual style of the interface. While modern interfaces have investigated compelling alternatives, using more creative shapes can prove to be a bit riskier. You need to ensure that people can easily identify which elements in the mobile app are actually buttons and not decorative graphics. Color and shading also help users quickly recognize which screen elements are actionable. For example, if a button casts a subtle shadow users tend to understand that the element is interactive.
In addition, each interactive element of a user interface should have a clear label or icon associated with it. The action button label should quickly convey a feature or task so that users know exactly what happens when they click that button. For example, ‘Create Account’ gives users a clear and specific outcome to pressing the button, providing confidence and eliminating the stress of doubt. Vague or abstract labels often don’t provide enough information about what will happen if the button is pressed. Users tend to avoid pressing anything that doesn’t provide clarity of result beforehand.
Further, button size and the touch area associated with it is of utmost importance. Button size plays a key role in helping users to identify elements of the user interface you may want to emphasize. Various platforms provide guidelines on minimum touch targets, with averages finger pads being measured between 10–14mm and fingertips at 10 mm x10 mm. CTA buttons should extend beyond these minimum sizes to help reduce missed taps by end users.
Button UX design is always about recognition and clarity. People have important and frequent dialogues with their mobile devices on a daily basis. CTA buttons play a vital role in this conversation.