Layout with rows, columns, and constraints

Flutter’s core layout mechanism relies entirely on widgets, including invisible layout models like rows, columns, and grids that arrange, constrain, and align visible elements. Build complex UIs by composing simple widgets, such as placing Text widgets inside Container widgets to add margins, or wrapping Rows in Containers for padding. Customize UIs via properties: use the color property for Icons, Text.style for font, color, and weight, and specific properties for Columns and Rows to control vertical/horizontal alignment and space occupation. Enable debugPaintSizeEnabled to visualize layouts for debugging purposes. Select layout widgets based on desired alignment or constraint characteristics, which are typically passed to contained widgets. For example, use Center to position a widget horizontally and vertically. This composition-based approach ensures that almost everything in the interface, from images to structural containers, functions as a widget. Scope: Flutter. Reviewed October 4, 2026.