flutter_recaptcha

A Flutter package that generates and validates distorted CAPTCHA images to secure your forms and authentication flows — no external service or API key required.

Features

• Custom CAPTCHA rendering — a CustomPainter draws randomly rotated, distorted CAPTCHA text.
• Background noise & distortion — randomized dots, lines, and circles make the CAPTCHA harder to read programmatically.
• Built-in validation — combines the CAPTCHA display with a text field and reports success/failure through a callback.
• Auto-regeneration — a new CAPTCHA is generated automatically after a failed attempt, or manually via the refresh button.
• Customizable — control the text style, field style, and widget size.

Getting started

Add the package to your pubspec.yaml:

dependencies:
  flutter_recaptcha: ^0.0.1

Then import it:

import 'package:flutter_recaptcha/flutter_recaptcha.dart';

Usage

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

class CaptchaExample extends StatefulWidget {
  const CaptchaExample({super.key});

  @override
  State<CaptchaExample> createState() => _CaptchaExampleState();
}

class _CaptchaExampleState extends State<CaptchaExample> {
  final TextEditingController _controller = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return CaptchaWidget(
      textField: TextField(
        controller: _controller,
        decoration: const InputDecoration(hintText: 'Enter the code above'),
      ),
      onVerified: (isValid) {
        if (isValid) {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(content: Text('Verified!')),
          );
        } else {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(content: Text('Incorrect code, try again.')),
          );
        }
      },
    );
  }
}

Tap the check icon to validate, or the refresh icon to generate a new CAPTCHA at any time.

See the example folder for a complete, runnable app.

Additional information

Found a bug or want a feature? Open an issue or pull request on the GitHub repository.