Password Strength Meter For Angular 18

To display the strength of the password with a visual feedback.

Password Strength Meter use zxcvbn to estimate the strength of the password and also provide a visual feedback with suggestions and warning messages.

This lib was developed based on the following tutorial.

How then is password strength measured? Dropbox developed an algorithm for a realistic password strength estimator inspired by password crackers. This algorithm is packaged in a Javascript library called zxcvbn. In addition, the package contains a dictionary of commonly used English words, names and passwords.

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Demo

See Demo Here

<password-strength-meter [password]="password"></password-strength-meter>

stackblitz

Get Started

Step 1: npm install (For Angular v17)

npm install @zxcvbn-ts/core@^3.0.0 @zxcvbn-ts/language-en@^3.0.0 angular-password-strength-meter --save

For Angular v15

npm install @zxcvbn-ts/core@^3.0.0 @zxcvbn-ts/language-en@^3.0.0 angular-password-strength-meter@^8.0.0 --save

Optional Packages: zxcvbn packagase are not required if PasswordStrengthMeterModule is using with a custom implementation of IPasswordStrengthMeterService .

Step 2: Use the provideZxvbnServiceForPSM in appConfig

....
import { bootstrapApplication } from '@angular/platform-browser';
import { ApplicationConfig } from '@angular/core';
import { provideZxvbnServiceForPSM } from 'angular-password-strength-meter/zxcvbn';
....

export const appConfig: ApplicationConfig = {
  providers: [provideZxvbnServiceForPSM()],
};

bootstrapApplication(AppComponent, appConfig).catch((err) =>
  console.error(err)
);

Step 3: Import the PasswordStrengthMeterComponent component in your app.component.ts

....
import { PasswordStrengthMeterComponent } from 'angular-password-strength-meter';
....

@Component({
  selector: 'app-root',
  standalone: true,
  imports: [
    CommonModule,
    PasswordStrengthMeterComponent,
  ],
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss'],
})
export class AppComponent {
  password: string = '';
}

Step 4: use the password-strength-meter component in your app.component.html

<password-strength-meter [password]="password" enableFeedback />

Use custom zxcvbn options for the password strength meter

You can override the default zxcvbn options by providing the config to provideZxvbnServiceForPSM(config?: ZxvbnConfigType)

....
import { bootstrapApplication } from '@angular/platform-browser';
import { ApplicationConfig } from '@angular/core';

import { translations } from '@zxcvbn-ts/language-en';
import { provideZxvbnServiceForPSM, ZxvbnConfigType } from 'angular-password-strength-meter/zxcvbn';
....

const zxvbnConfig: ZxvbnConfigType = {
  translations: translations,
};

export const appConfig: ApplicationConfig = {
  providers: [provideZxvbnServiceForPSM(zxvbnConfig)],
};

bootstrapApplication(AppComponent, appConfig).catch((err) =>
  console.error(err)
);

Refer to the zxcvbn documentation for more information.

Use custom password strength meter service

You can override the default password strength meter service by providing the Custom Service class

....
import { Injectable } from '@angular/core';
import { IPasswordStrengthMeterService } from 'angular-password-strength-meter';

@Injectable()
export class CustomPsmServiceService extends IPasswordStrengthMeterService {
  score(password: string): number {
    // TODO - return score 0 - 4 based on password
    return 1;
  }

  scoreWithFeedback(password: string): FeedbackResult {
    // TODO - return score with feedback
    return { score: 1, feedback: { warning: '', suggestions: [] } };
  }

   scoreAsync(password: string): Promise<number> {
    // TODO - do some async operation
    return new Promise();
  }

  scoreWithFeedbackAsync(password: string): Promise<FeedbackResult> {
    // TODO - do some async operation
    return new Promise();
  }
}
....

@Component({
  selector: 'app-custom-service',
  standalone: true,
  imports: [CommonModule, FormsModule, PasswordStrengthMeterComponent],
  providers: [
    {
      provide: IPasswordStrengthMeterService,
      useClass: CustomPsmServiceService,
    },
  ],
  templateUrl: './custom-service.component.html',
  styleUrl: './custom-service.component.scss',
})
export class CustomServiceComponent {
  text: string = '';
  score: number | null = null;

  public onPasswordStrengthChange(score: number | null) {
    this.score = score;
  }
}

API

option	bind	type	default	description
password	Input()	string	-	password to calculate its strength
minPasswordLength	Input()	number	8	min length of password to calculate the strength
enableFeedback	Input()	boolean	false	to show/hide the suggestions and warning messages
numberOfProgressBarItems	Input()	number	5	change the number to update the number of progress bar items
enableAsync	Input()	boolean	false	to do the score calculation in async mode
colors	Input()	string[]	['darkred', 'orangered', 'orange', 'yellowgreen', 'green']	to overide the meter colors, password strength range is 0 - 4, for strength 0 equals first color in the array and so on. Note - length of the colors array should match the number of progress bar items
strengthChange	Output()	number	-	emits the strength of the provided password in number -> range 0 - 4