ion-checkbox
Checkboxes allow the selection of multiple options from a set of options. They appear as checked (ticked) when activated. Clicking on a checkbox will toggle the checked property. They can also be checked programmatically by setting the checked property.
Basic Usage
Label Placement
Developers can use the labelPlacement property to control how the label is placed relative to the control. This property mirrors the flexbox flex-direction property.
Alignment
Developers can use the alignment property to control how the label and control are aligned on the cross axis. This property mirrors the flexbox align-items property.
Stacked checkboxes can be aligned using the alignment property. This can be useful when the label and control need to be centered horizontally.
Justification
Developers can use the justify property to control how the label and control are packed on a line. This property mirrors the flexbox justify-content property.
ion-item is only used in the demos to emphasize how justify works. It is not needed in order for justify to function correctly.
Indeterminate Checkboxes
Links inside of Labels
Checkbox labels can sometimes be accompanied with links. These links can provide more information related to the checkbox. However, clicking the link should not check the checkbox. To achieve this, we can use stopPropagation to prevent the click event from bubbling. When using this approach, the rest of the label still remains clickable.
Theming
CSS Custom Properties
Interfaces
CheckboxChangeEventDetail
interface CheckboxChangeEventDetail<T = any> {
value: T;
checked: boolean;
}
CheckboxCustomEvent
While not required, this interface can be used in place of the CustomEvent interface for stronger typing with Ionic events emitted from this component.
interface CheckboxCustomEvent<T = any> extends CustomEvent {
detail: CheckboxChangeEventDetail<T>;
target: HTMLIonCheckboxElement;
}
Migrating from Legacy Checkbox Syntax
A simpler checkbox syntax was introduced in Ionic 7.0. This new syntax reduces the boilerplate required to setup a checkbox, resolves accessibility issues, and improves the developer experience.
Developers can perform this migration one checkbox at a time. While developers can continue using the legacy syntax, we recommend migrating as soon as possible.
Using the Modern Syntax
Using the modern syntax involves removing the ion-label and passing the label directly inside of ion-checkbox. The placement of the label can be configured using the labelPlacement property on ion-checkbox. The way the label and the control are packed on a line can be controlled using the justify property on ion-checkbox.
- JavaScript
- Angular
- React
- Vue
<!-- Basic -->
<!-- Before -->
<ion-item>
<ion-label>Checkbox Label</ion-label>
<ion-checkbox></ion-checkbox>
</ion-item>
<!-- After -->
<ion-item>
<ion-checkbox>Checkbox Label</ion-checkbox>
</ion-item>
<!-- Fixed Labels -->
<!-- Before -->
<ion-item>
<ion-label position="fixed">Checkbox Label</ion-label>
<ion-checkbox></ion-checkbox>
</ion-item>
<!-- After -->
<ion-item>
<ion-checkbox label-placement="fixed">Checkbox Label</ion-checkbox>
</ion-item>
<!-- Checkbox at the start of line, Label at the end of line -->
<!-- Before -->
<ion-item>
<ion-label slot="end">Checkbox Label</ion-label>
<ion-checkbox></ion-checkbox>
</ion-item>
<!-- After -->
<ion-item>
<ion-checkbox label-placement="end">Checkbox Label</ion-checkbox>
</ion-item>
<!-- Basic -->
<!-- Before -->
<ion-item>
<ion-label>Checkbox Label</ion-label>
<ion-checkbox></ion-checkbox>
</ion-item>
<!-- After -->
<ion-item>
<ion-checkbox>Checkbox Label</ion-checkbox>
</ion-item>
<!-- Fixed Labels -->
<!-- Before -->
<ion-item>
<ion-label position="fixed">Checkbox Label</ion-label>
<ion-checkbox></ion-checkbox>
</ion-item>
<!-- After -->
<ion-item>
<ion-checkbox labelPlacement="fixed">Checkbox Label</ion-checkbox>
</ion-item>
<!-- Checkbox at the start of line, Label at the end of line -->
<!-- Before -->
<ion-item>
<ion-label slot="end">Checkbox Label</ion-label>
<ion-checkbox></ion-checkbox>
</ion-item>
<!-- After -->
<ion-item>
<ion-checkbox labelPlacement="end">Checkbox Label</ion-checkbox>
</ion-item>
{/* Basic */}
{/* Before */}
<IonItem>
<IonLabel>Checkbox Label</IonLabel>
<IonCheckbox></IonCheckbox>
</IonItem>
{/* After */}
<IonItem>
<IonCheckbox>Checkbox Label</IonCheckbox>
</IonItem>
{/* Fixed Labels */}
{/* Before */}
<IonItem>
<IonLabel position="fixed">Checkbox Label</IonLabel>
<IonCheckbox></IonCheckbox>
</IonItem>
{/* After */}
<IonItem>
<IonCheckbox labelPlacement="fixed">Checkbox Label</IonCheckbox>
</IonItem>
{/* Checkbox at the start of line, Label at the end of line */}
{/* Before */}
<IonItem>
<IonLabel slot="end">Checkbox Label</IonLabel>
<IonCheckbox></IonCheckbox>
</IonItem>
{/* After */}
<IonItem>
<IonCheckbox labelPlacement="end">Checkbox Label</IonCheckbox>
</IonItem>
<!-- Basic -->
<!-- Before -->
<ion-item>
<ion-label>Checkbox Label</ion-label>
<ion-checkbox></ion-checkbox>
</ion-item>
<!-- After -->
<ion-item>
<ion-checkbox>Checkbox Label</ion-checkbox>
</ion-item>
<!-- Fixed Labels -->
<!-- Before -->
<ion-item>
<ion-label position="fixed">Checkbox Label</ion-label>
<ion-checkbox></ion-checkbox>
</ion-item>
<!-- After -->
<ion-item>
<ion-checkbox label-placement="fixed">Checkbox Label</ion-checkbox>
</ion-item>
<!-- Checkbox at the start of line, Label at the end of line -->
<!-- Before -->
<ion-item>
<ion-label slot="end">Checkbox Label</ion-label>
<ion-checkbox></ion-checkbox>
</ion-item>
<!-- After -->
<ion-item>
<ion-checkbox label-placement="end">Checkbox Label</ion-checkbox>
</ion-item>
In past versions of Ionic, ion-item was required for ion-checkbox to function properly. Starting in Ionic 7.0, ion-checkbox should only be used in an ion-item when the item is placed in an ion-list. Additionally, ion-item is no longer required for ion-checkbox to function properly.
Using the Legacy Syntax
Ionic uses heuristics to detect if an app is using the modern checkbox syntax. In some instances, it may be preferable to continue using the legacy syntax. Developers can set the legacy property on ion-checkbox to true to force that instance of the checkbox to use the legacy syntax.
Properties
alignment
| Description | How to control the alignment of the checkbox and label on the cross axis. "start": The label and control will appear on the left of the cross axis in LTR, and on the right side in RTL. "center": The label and control will appear at the center of the cross axis in both LTR and RTL. |
| Attribute | alignment |
| Type | "center" | "start" |
| Default | 'center' |
checked
| Description | If true, the checkbox is selected. |
| Attribute | checked |
| Type | boolean |
| Default | false |
color
| Description | The color to use from your application's color palette. Default options are: "primary", "secondary", "tertiary", "success", "warning", "danger", "light", "medium", and "dark". For more information on colors, see theming. |
| Attribute | color |
| Type | "danger" | "dark" | "light" | "medium" | "primary" | "secondary" | "success" | "tertiary" | "warning" | string | undefined |
| Default | undefined |
disabled
| Description | If true, the user cannot interact with the checkbox. |
| Attribute | disabled |
| Type | boolean |
| Default | false |
indeterminate
| Description | If true, the checkbox will visually appear as indeterminate. |
| Attribute | indeterminate |
| Type | boolean |
| Default | false |
justify
| Description | How to pack the label and checkbox within a line. "start": The label and checkbox will appear on the left in LTR and on the right in RTL. "end": The label and checkbox will appear on the right in LTR and on the left in RTL. "space-between": The label and checkbox will appear on opposite ends of the line with space between the two elements. |
| Attribute | justify |
| Type | "end" | "space-between" | "start" |
| Default | 'space-between' |