Flutter Screen Lock

This Flutter plugin provides an feature for screen lock. Enter your passcode to unlock the screen. You can also use biometric authentication as an option.

Landscape view


  • By the length of the character count
  • You can change Cancel and Delete widget
  • Optimizes the UI for device size and orientation
  • You can disable cancellation
  • You can use biometrics (local_auth plugin)
  • Biometrics can be displayed on first launch
  • Unlocked callback
  • You can specify a mismatch event.
  • Limit the maximum number of retries


You can easily lock the screen with the following code.
To unlock, enter correctString.


If you give the same input as correctString, it will automatically close the screen.

import 'package:flutter_screen_lock/flutter_screen_lock.dart';

  context: context,
  correctString: '1234',

Block user

Provides a screen lock that cannot be cancelled.

import 'package:flutter_screen_lock/flutter_screen_lock.dart';

  context: context,
  correctString: '1234',
  canCancel: false,

Passcode creation

You can have users create a new passcode with confirmation

import 'package:flutter_screen_lock/flutter_screen_lock.dart';

  context: context,
  onConfirmed: (value) => print(value), // store new passcode somewhere here

Control the creation state

import 'package:flutter_screen_lock/flutter_screen_lock.dart';

final inputController = InputController();

  context: context,
  inputController: inputController,

// Somewhere else...
inputController.unsetConfirmed(); // reset first and confirm input

Use local_auth

Add the local_auth package to pubspec.yml.

It includes an example that calls biometrics as soon as screenLock is displayed in didOpened.

import 'package:flutter_screen_lock/flutter_screen_lock.dart';
import 'package:local_auth/local_auth.dart';
import 'package:flutter/material.dart';

Future<void> localAuth(BuildContext context) async {
  final localAuth = LocalAuthentication();
  final didAuthenticate = await localAuth.authenticateWithBiometrics(
      localizedReason: 'Please authenticate');
  if (didAuthenticate) {

  context: context,
  correctString: '1234',
  customizedButtonChild: Icon(Icons.fingerprint),
  customizedButtonTap: () async => await localAuth(context),
  didOpened: () async => await localAuth(context),

Fully customize

You can customize every aspect of the screenlock. Here is an example:

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

  context: context,
  title: const Text('change title'),
  confirmTitle: const Text('change confirm title'),
  onConfirmed: (value) => Navigator.of(context).pop(),
  config: const ScreenLockConfig(
    backgroundColor: Colors.deepOrange,
  secretsConfig: SecretsConfig(
    spacing: 15, // or spacingRatio
    padding: const EdgeInsets.all(40),
    secretConfig: SecretConfig(
      borderColor: Colors.amber,
      borderSize: 2.0,
      disabledColor: Colors.black,
      enabledColor: Colors.amber,
      height: 15,
      width: 15,
      build: (context,
              {required config, required enabled}) =>
        decoration: BoxDecoration(
          shape: BoxShape.rectangle,
          color: enabled
              ? config.enabledColor
              : config.disabledColor,
          border: Border.all(
            width: config.borderSize,
            color: config.borderColor,
        padding: const EdgeInsets.all(10),
        width: config.width,
        height: config.height,
  keyPadConfig: KeyPadConfig(
    buttonConfig: StyledInputConfig(
        color: Colors.orange,
        fontWeight: FontWeight.bold,
      buttonStyle: OutlinedButton.styleFrom(
        shape: const RoundedRectangleBorder(),
        backgroundColor: Colors.deepOrange,
    displayStrings: [
  cancelButton: const Icon(Icons.close),
  deleteButton: const Icon(Icons.delete),

Version migration

8.x to 9 migration

  • Change screenLockConfig parameter to config
  • Change keyPadConfig parameter to config

7.x to 8 migration

  • Change all callback names from didSomething to onSomething
  • Change screenLock with confirm: true to screenLockCreate
  • Change ScreenLock with confirm: true to ScreenLock.create
  • Replace StyledInputConfig with KeyPadButtonConfig
  • Replace spacingRatio with fixed value spacing in Secrets

6.x to 7 migration

  • Requires dart >= 2.17 and Flutter 3.0
  • Replace InputButtonConfig with KeyPadConfig.
  • Change delayChild to delayBuilder.
    delayBuilder is no longer displayed in a new screen. Instead, it is now located above the Secrets.
  • Accept BuildContext in secretsBuilder.

5.x to 6 migration

  • ScreenLock does not use Navigator.pop internally anymore.
    The developer should now pop by themselves when desired.
    screenLock call will pop automatically if onUnlocked is null.

4.x to 5 migration

Import name has changed from:

import 'package:flutter_screen_lock/functions.dart';


import 'package:flutter_screen_lock/flutter_screen_lock.dart';

Apps that use this library


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