Biometric Signature is a Flutter plugin that simplifies the process of integrating biometric authentication (fingerprint, facial, and iris recognition) into your Dart and Flutter applications. It is designed to provide a consistent user experience across both Android and iOS platforms, with customizable UI components and high-level abstractions for biometric signature management.


  • Cross-platform support (Android and iOS)
  • Fingerprint, facial, and iris recognition (based on device capabilities)
  • Simple integration with Dart and Flutter applications
  • Customizable UI components for signature prompts
  • High-level abstractions for managing biometric signatures

Getting Started

To get started with Biometric Signature, follow these steps:

  1. Add the package to your project by including it in your pubspec.yaml file:
  biometric_signature: ^2.1.0
Android iOS
Support SDK 23+ 12.0+

iOS Integration

This plugin works with Touch ID or Face ID. To use Face ID in available devices, you need to add:

    <string>This app is using FaceID for authentication</string>

to your Info.plist file.

Android Integration

Activity Changes

This plugin requires the use of a FragmentActivity as opposed to Activity. This can be easily done by switching to use FlutterFragmentActivity as opposed to FlutterActivity in your manifest or your own Activity class if you are extending the base class.


Update your project's AndroidManifest.xml file to include the USE_BIOMETRIC permission.

<manifest xmlns:android="" package="">
    <uses-permission android:name="android.permission.USE_BIOMETRIC" />
  1. Import the package in your Dart code:
import 'package:biometric_signature/biometric_signature.dart';
  1. Initialize the Biometric Signature instance:

final biometricSignature = BiometricSignature();


import 'package:flutter/material.dart';
import 'package:biometric_signature/biometric_signature.dart';

void main() {

class MyApp extends StatelessWidget {
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('Biometric Signature Example')),
        body: Center(child: BiometricAuthButton()),

class BiometricAuthButton extends StatelessWidget {
  final BiometricSignature _biometricSignature = BiometricSignature();

  Widget build(BuildContext context) {
    return ElevatedButton(
      child: Text('Authenticate with Biometrics'),
      onPressed: () async {
        final biometrics = await _biometricSignature
        if (!biometrics!.contains("none, ")) {
          try {
            final String? publicKey = await _biometricSignature
            final String? signature = await _biometricSignature
                options: {
                  "payload": "Payload to sign",
                  "promptMessage": "You are Welcome!"});
          } on PlatformException catch (e) {