The primary action button is not a decorative element at the bottom of a screen. It completes a user decision and communicates what will happen next. If its label is vague, its contrast is weak, or loading is unclear, the interface creates doubt at the most important moment.
One action, one emphasis
The main outcome should be obvious. “Continue,” “Save,” “Pay,” or “Send” describe a consequence better than a generic “Next.” A secondary action can be quieter, but it should not be hidden.
Button states
- available when the action is possible;
- unavailable with an explanation when data is missing;
- active with a progress state while the request runs;
- successful or failed with a clear next step.
Do not change the button or field in a way that leaves users unsure whether a request was sent. For file uploads or slow networks, prevent repeat taps, preserve data, and show progress.
Android quality guidance recommends consistent platform patterns. This also matters for accessibility: buttons need a sufficient touch target, visible focus, and a meaningful screen-reader label.
Test more than successful taps. Include errors, slow responses, repeat submissions, and back navigation. A good button does not only improve conversion; it reduces uncertainty and accidental actions.
Source: Android Developers: What a great user experience looks like.
