<mat-expansion-panel> provides an expandable details-summary view.

Expansion-panel content

Header

The <mat-expansion-panel-header> shows a summary of the panel content and acts as the control for expanding and collapsing. This header may optionally contain an <mat-panel-title> and an <mat-panel-description>, which format the content of the header to align with Material Design specifications.

By default, the expansion-panel header includes a toggle icon at the end of the header to indicate the expansion state. This icon can be hidden via the hideToggle property.

Action bar

Actions may optionally be included at the bottom of the panel, visible only when the expansion is in its expanded state.

Disabling a panel

Expansion panels can be disabled using the disabled attribute. A disabled expansion panel can't be toggled by the user, but can still be manipulated programmatically.

Accordion

Multiple expansion-panels can be combined into an accordion. The multi="true" input allows the expansions state to be set independently of each other. When multi="false" (default) just one panel can be expanded at a given time:

Lazy rendering

By default, the expansion panel content will be initialized even when the panel is closed. To instead defer initialization until the panel is open, the content should be provided as an ng-template:

<mat-expansion-panel>
  <mat-expansion-panel-header>
    This is the expansion title
  </mat-expansion-panel-header>

  <ng-template matExpansionPanelContent>
    Some deferred content
  </ng-template>
</mat-expansion-panel>

Accessibility

MatExpansionPanel imitates the experience of the native <details> and <summary> elements. The expansion panel header applies role="button" and the aria-controls attribute with the content element's ID.

Because expansion panel headers are buttons, avoid adding interactive controls as children of <mat-expansion-panel-header>, including buttons and anchors.