Angular 2 Checkbox Two Way Data Binding

You can remove .selected from saveUsername in your checkbox input since saveUsername is a boolean. Instead of [(ngModel)] use [checked]="saveUsername" (change)="saveUsername = !saveUsername"

Edit: Correct Solution:

<input  type="checkbox"  [checked]="saveUsername"  (change)="saveUsername = !saveUsername"/>

Update: Like @newman noticed when ngModel is used in a form it won't work. However, you should use [ngModelOptions] attribute like (tested in Angular 7):

<input  type="checkbox"  [(ngModel)]="saveUsername"  [ngModelOptions]="{standalone: true}"/> `

I also created an example at Stackblitz: https://stackblitz.com/edit/angular-abelrm

Unfortunately solution provided by @hakani is not two-way binding. It just handles One-way changing model from UI/FrontEnd part.

Instead the simple:

<input [(ngModel)]="checkboxFlag" type="checkbox"/>

will do two-way binding for checkbox.

Afterwards, when Model checkboxFlag is changed from Backend or UI part - voila, checkboxFlag stores actual checkbox state.

To be sure I've prepared Plunker code to present the result : https://plnkr.co/edit/OdEAPWRoqaj0T6Yp0Mfk

Just to complete this answer you should include the import { FormsModule } from '@angular/forms' into app.module.ts and add to imports array i.e

import { FormsModule } from '@angular/forms';[...]@NgModule({  imports: [    [...]    FormsModule  ],  [...]})

I'm working with Angular5 and I had to add the "name" attribute to get the binding to work... The "id" is not required for binding.

<input type="checkbox" id="rememberMe" name="rememberMe" [(ngModel)]="rememberMe">