Radio buttons are simple UI elements that let users select one option from a list. They are lightweight and have minimal impact on frame rate and memory. Typically, they do not cause frame drops and use very little battery. However, if you have many radio buttons in a long list, rendering all at once can slightly affect scrolling smoothness.
To keep your app smooth at 60 frames per second, use Flutter's built-in Radio widget efficiently. Avoid rebuilding the entire list of radio buttons on every state change. Instead, update only the selected radio button's state. Use ListView.builder for long lists to build items on demand. Also, keep the widget tree shallow and avoid unnecessary animations around radio buttons.
Radio buttons use Flutter's core widgets and do not add extra package size. They have negligible impact on app bundle size and startup time. Using standard Radio widgets keeps your app lightweight. Custom radio button packages or heavy styling might increase size slightly, so prefer Flutter's default widgets for minimal impact.
Flutter's Radio widget looks consistent across platforms by default. However, iOS users expect a different style called segmented controls or toggles instead of classic radio circles. To match platform conventions, consider using CupertinoSegmentedControl on iOS and Radio on Android. Also, iOS apps require accessibility labels for VoiceOver, and Android apps need content descriptions for TalkBack. Flutter supports both with semantic widgets.
If your screen with radio buttons loads slowly, it is probably because you are building too many widgets at once or doing heavy work on the main thread. Avoid creating large static lists of radio buttons without lazy loading. Also, check if you are performing expensive computations or network calls during build. Optimize by using ListView.builder and moving heavy tasks off the UI thread.