Badges are small status descriptors for UI elements. A badge consists of a small circle, typically containing a number or other short set of characters, that appears in proximity to another object.
Text with a badge4
Button with a badge on the left
Icon with a badge home15Example with a home icon with overlaid badge showing the number 15
By default, the badge will be placed above after. The direction can be changed by defining the attribute matBadgePosition follow by above|below and before|after.
<mat-icon matBadge="22" matBadgePosition="above after">home</mat-icon>
The overlap of the badge in relation to its inner contents can also be defined using the matBadgeOverlap tag. Typically, you want the badge to overlap an icon and not a text phrase. By default it will overlap.
<h1 matBadge="11" matBadgeOverlap="false">
The badge has 3 sizes: small, medium and large. By default, the badge is set to medium. You can change the size by adding matBadgeSize to the host element.
<h1 matBadge="11" matBadgeSize="large">
The badge visibility can be toggled programmatically by defining matBadgeHidden.
<h1 matBadge="11" [matBadgeHidden]="!visible">
Badges can be colored in terms of the current theme using the matBadgeColor property to set the background color to primary, accent, or warn.
<mat-icon matBadge="22" matBadgeColor="accent">
Badges should be given a meaningful description via matBadgeDescription. This description will be applied, via aria-describedby to the element decorated by matBadge.
When applying a badge to a <mat-icon>, it is important to know that the icon is marked as aria-hidden by default. If the combination of icon and badge communicates some meaningful information, that information should be surfaced in another way. See the guidance on indicator icons for more information.