Angular Material Stepper: Custom Styling Tips

The Angular Material Stepper component provides a sleek and intuitive way to guide users through multi-step workflows. Out of the box, it offers a clean design aligned with Material Design standards. However, many projects call for a more personalized appearance to match a brand or product style. Fortunately, Angular Material allows extensive customization of the Stepper’s appearance with a bit of CSS and an understanding of its structure.

Here’s a practical guide to help you tailor the Angular Material Stepper to your needs.

Understanding the DOM Structure

Before diving into styling, it’s helpful to inspect the rendered DOM of the Stepper. Angular Material uses encapsulated styles via the ::ng-deep combinator or global style overrides, which are necessary when targeting internal components like step headers and icons.

Each step in the stepper consists of:

• A step header with an icon or label
• A step label container
• A step content container

Using browser developer tools, you can find classes like .mat-step-header, .mat-step-icon, and .mat-step-label. These are key targets for customization.

Customizing Step Icons

By default, the Stepper uses numbered circles as step indicators. To apply custom styles or even replace the icons:

::ng-deep .mat-step-icon {
  background-color: #3f51b5
  color: white
  font-weight: bold
}

::ng-deep .mat-step-icon.mat-step-icon-selected {
  background-color: #ff4081
}

::ng-deep .mat-step-icon.mat-step-icon-state-done {
  background-color: #4caf50
}

If you want to completely replace the icons with your own SVGs or font icons, you can use the matStepperIcon directive:

<mat-stepper>
  <ng-template matStepperIcon="edit">
    <mat-icon>edit</mat-icon>
  </ng-template>
</mat-stepper>

This method allows contextual icon customization based on state.

Styling Step Labels

You can enhance label typography or apply a dynamic style when a step is selected:

::ng-deep .mat-step-label {
  font-size: 16px
  color: #666
}

::ng-deep .mat-step-header.mat-active .mat-step-label {
  color: #ff4081
  font-weight: bold
}

Adjusting Connector Lines

The lines between steps are known as connectors. You can override their color and thickness by targeting .mat-stepper-horizontal-line or .mat-stepper-vertical-line:

::ng-deep .mat-stepper-horizontal-line {
  border-top-width: 3px
  border-color: #3f51b5
}

For vertical steppers, use .mat-stepper-vertical-line accordingly.

Theming with Angular Material

To make your changes more maintainable and theme-aware, consider using Angular Material’s theming system. If you’re using SCSS, you can define your own theme and include mixins like:

@include mat-stepper-theme($my-custom-theme)

This approach ensures consistent color schemes across the component while keeping your overrides manageable.

Best Practices

• Use ::ng-deep cautiously since it’s deprecated and may be removed in future versions. Prefer encapsulation via global styles or custom wrappers when possible.
• For large customizations, create your own wrapper component that styles the Stepper internally using ViewEncapsulation.None.
• Always test accessibility after customizing visuals, especially if you change icons or interaction cues.

Customizing the Angular Material Stepper allows you to deliver a guided workflow experience that feels native to your application. With a thoughtful approach to styling and structure, you can go beyond the default and design a Stepper that’s both functional and uniquely yours. Happy Coding!