Flutter Biometric Authentication: A Comprehensive Guide

Flutter Biometric Authentication: A Comprehensive Guide

Quick Summary: Delve into the world of Flutter Biometric Authentication with this comprehensive guide. Learn how to implement cutting-edge biometric technologies, such as fingerprint and facial recognition, in Flutter apps, enhancing security and providing a seamless, user-friendly authentication experience for your app users.


Biometric authentication has become a popular and secure way to verify the identity of users in mobile applications. Flutter, Google's UI toolkit for building natively compiled applications for mobile, web, and desktop from a single codebase, provides excellent support for implementing biometric authentication. In this article, we will explore how to integrate biometric authentication into a Flutter app using the `local_auth` package.

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Setting Up the Project

Before we dive into the implementation, make sure you have Flutter installed on your machine. Create a new Flutter project using the following command:

flutter create biometric_auth_demo

cd biometric_auth_demo


Now, open the `pubspec.yaml` file and add the `local_auth` package:



    sdk: flutter

  local_auth: ^2.0.1


Run `flutter pub get` to fetch and install the dependencies.

Implementing Biometric Authentication

1. Import the necessary packages: Open the `main.dart` file and import the required packages:


import 'package:flutter/material.dart';

import 'package:local_auth/local_auth.dart';


2. Create a `LocalAuthentication` instance: Create an instance of `LocalAuthentication` to interact with the biometric authentication services:

final LocalAuthentication _localAuthentication = LocalAuthentication();


3. Check for Biometric Support: Before attempting to authenticate, check if the device supports biometric authentication:


Future<void> checkBiometric() async {

  bool canCheckBiometrics = await _localAuthentication.canCheckBiometrics;

  print('Biometrics supported: $canCheckBiometrics');



4. Retrieve Available Biometrics: You can also retrieve the types of biometrics available on the device:


Future<void> getAvailableBiometrics() async {

  List<BiometricType> availableBiometrics = await _localAuthentication.getAvailableBiometrics();

  print('Available biometrics: $availableBiometrics');



5. Authenticate with Biometrics: Now, let's implement the biometric authentication:


Future<void> authenticate() async {

  bool isAuthenticated = false;

  try {

    isAuthenticated = await _localAuthentication.authenticate(

      localizedReason: 'Authenticate to access the app',

      biometricOnly: true,

      useErrorDialogs: true,

      stickyAuth: true,


  } catch (e) {

    print('Error during biometric authentication: $e');


  if (isAuthenticated) {

    print('Biometric authentication successful');

  } else {

    print('Biometric authentication failed');




6. UI Integration: Create a simple UI to trigger biometric authentication:


void main() => runApp(MyApp());

class MyApp extends StatelessWidget {


  Widget build(BuildContext context) {

    return MaterialApp(

      home: Scaffold(

        appBar: AppBar(

          title: Text('Biometric Auth Demo'),


        body: Center(

          child: ElevatedButton(

            onPressed: () async {

              await checkBiometric();

              await getAvailableBiometrics();

              await authenticate();


            child: Text('Authenticate with Biometrics'),









We explored how to integrate biometric authentication into a Flutter app using the `local_auth` package. By following the steps outlined above, you can enhance the security of your Flutter applications while providing a seamless and user-friendly authentication experience. Remember to handle errors appropriately and customize the authentication flow to meet the specific requirements of your app.

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Kshitiz Sharma

Kshitiz Sharma

A mobile app developer on a relentless quest for excellence, fueled by a passion for innovation. I am a dedicated explorer in the world of code, always pushing the limits, and love creating apps that work wonders.