BotDetect PHP CAPTCHA Generator

Unlike Recaptcha the Stalker -- BotDetect CAPTCHA works in China! Licensable source-code; self-hosted -- doesn't stalk -- nor does it slurp your form-data! Think: GDPR & LGPD!

PHP CAPTCHA Generator Highlights:

NATIONAL-SECURITY & PRIVACY FRIENDLY:
Self-hosted PHP Captcha library -- no 3rd-party servers involved
Where having no 3rd-party servers involved also means:
- no QUIC server-config/source-address-token & n-RTT session resumption
- no TLS v1.3 PSK & n-RTT session resumption
- no TLS v1.2 Session Ticket / Session ID session resumption
- no cross-domain-shared TLS states
- no TLS Channel IDs
- no Token Binding
- no old-school cookies-based ways of user identification and stalking
From a vendor that is not in the stalking business
- nor a part of PRISM or XKeyscore
- nor has anything to do with the NSA
Lets you never have 3rd-parties:
- identify and stalk users on your site
- slurp national-security-sensitive or privacy-sensitive form-data from your site
Plays nicely with Firefox, TOR Browser, and VPN users
NOTHING TO HIDE HERE:
Licensable source-code (PHP/JavaScript) -- to fit neatly in your code audit processes
MULTINATIONALS FRIENDLY:
Works in China
Allows for EU GDPR and Brazilian LGPD compliant sites -- no need to risk those enormous multi-million dollar fines
56 audio localizations (including all 24 official EU languages) let you treat each local market with that particular local market's familiar combination of script and language
EASY FRONTEND INTEGRATIONS:
Out-of-the-box integrations with various JavaScript frontends:
- jQuery Captcha Plugin
- AngularJS and Angular Captcha Modules
- React Captcha Component
EASY BACKEND INTEGRATIONS:
Out-of-the-box integrations with various PHP backends:
- WordPress CAPTCHA Plugin
- Symfony CAPTCHA Bundle
- Laravel Captcha Package
- CakePHP Captcha Plugin
- CodeIgniter CAPTCHA Library
DEVOPS FRIENDLY:
TestMode-enabled -- ready for your CI/CD pipelines
ACCESSIBLE:
Produces XHTML 1.1 Strict, Section 508 and WCAG AAA compliant markup
Accompanied with legible images and recognizable audios
MISCELLANEOUS:
60 secure & readable Captcha image styles
20 secure & accessible audio Captcha sound styles
Custom Captcha image size, code length, css & icons, tooltips, and pretty much everything else...
Full support for all major browsers and all Android & iOS devices

Quickstarts:

BotDetect PHP Captcha generator allows you to easily add Captcha protection to various types of PHP based web forms.

We'll use default Captcha generator settings; to see how powerful and customizable BotDetect is, check the BotDetect features demo.

Plain PHP
CakePHP
CodeIgniter
Laravel
Symfony

1. Copy Captcha Library Files

Copy botdetect.php and the botdetect folder to your website folder. These files are included in the BotDetect download package (the lib sub-folder).

2. Show a Captcha Challenge on the Form

On the very top of the source file for the PHP form you want to protect against bots, add:

<?php session_start(); ?>
<?php require("botdetect.php"); ?>

On the PHP form you want to protect against bots, add:

  <link type="text/css" rel="Stylesheet" 
    href="<?php echo CaptchaUrls::LayoutStylesheetUrl() ?>" />
</head>

  […]

<?php // Adding BotDetect Captcha to the page 
  $ExampleCaptcha = new Captcha("ExampleCaptcha");
  $ExampleCaptcha->UserInputID = "CaptchaCode";
  echo $ExampleCaptcha->Html(); 
?>

<input name="CaptchaCode" id="CaptchaCode" type="text" />

3. Check User Input During Form Submission

When the form is submitted, the Captcha validation result must be checked:

<?php 
  if ($_POST) {
    // validate the Captcha to check we're not dealing with a bot
    $isHuman = $ExampleCaptcha->Validate();
    
    if (!$isHuman) {
      // TODO: Captcha validation failed, show error message
    } else {
      // TODO: Captcha validation passed, perform protected action
    } 
  }
?>

In-Depth PHP CAPTCHA Instructions and Explanations

Detailed PHP Captcha instructions and explanations can be found in the PHP Captcha integration how to guide.

CakePHP 3
CakePHP 2

1. Installing the BotDetect CakePHP Captcha Composer Plugin

Step 1: Install the BotDetect CakePHP Captcha Composer Plugin:

Run the following command in your application's root directory:

Step 2: Load the BotDetect CakePHP Captcha Composer Plugin in your application's bootstrap (<MY_CAKE_WEBROOT>/config/bootstrap.php):

Plugin::load('CakeCaptcha', ['routes' => true]);

2. Show a Captcha Challenge on the Form

Captcha configuration options (/config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return [
  // Captcha configuration for example page
  'ExampleCaptcha' => [
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ],
  
];

Load the BotDetect CakePHP component:

<?php namespace App\Controller;

use App\Controller\AppController;

class ExampleController extends AppController
{
  public function initialize()
  {
    parent::initialize();

    // load the Captcha component and set its parameter
    $this->loadComponent('CakeCaptcha.Captcha', [
      'captchaConfig' => 'ExampleCaptcha'
    ]);
  }
}

Showing a Captcha challenge in a View:

<!-- include the BotDetect layout stylesheet -->
<?= $this->Html->css(captcha_layout_stylesheet_url(), ['inline' => false]) ?>
</head>
  
  [...]

  <!-- show captcha image -->
  <?= captcha_image_html() ?>


  <!-- Captcha code user input textbox -->
  <?= $this->Form->input('CaptchaCode', [
    'label' => 'Retype the characters from the picture:',
    'maxlength' => '10',
    'style' => 'width: 270px;',
    'id' => 'CaptchaCode'
  ]) ?>

3. Check User Input During Form Submission

When a form is submitted, Captcha validation result must be checked in a Controller code:

if ($this->request->is('post')) {

  // validate the user-entered Captcha code
  $isHuman = captcha_validate($this->request->data['CaptchaCode']);

  // clear previous user input, since each Captcha code can only be validated once
  unset($this->request->data['CaptchaCode']);
 
  if ($isHuman) {
      // TODO: Captcha validation passed, perform protected action
  } else {
      // TODO: Captcha validation failed, show error message
  }
}

In-Depth CakePHP CAPTCHA Instructions and Explanations

Detailed CakePHP Captcha instructions and explanations can be found in the CakePHP 3 Captcha integration how to guide.

1. Copy CakePHP Captcha Plugin Files

Path Aliases Used Throughout This Guide

<MYCAKEAPP>: your CakePHP app directory (same as the APP_DIR PHP CakePHP constant)
<BDCAKEPACK>: the downloaded and extracted contents of the BotDetect Captcha CakePHP Package

Download the BotDetect Captcha CakePHP integration package and copy:
<BDCAKEPACK>/bd-captcha-cakephp-2-examples/ app/Plugin/BotDetect
to:
<MYCAKEAPP>/Plugin/BotDetect
Copy BotDetect PHP Captcha library from:
<BDCAKEPACK>/bd-captcha-cakephp-2-examples/ app/Lib
to:
<MYCAKEAPP>/Lib

2. Show a Captcha Challenge on the Form

Load the BotDetect Captcha CakePHP plugin in your application's bootstrap (<MYCAKEAPP>/Config/bootstrap.php):

CakePlugin::load(array(
  'BotDetect' => array('routes' => true)
));

Captcha configuration options (<MYCAKEAPP>/Config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

$config = array(
  // Captcha configuration for example page
  'ExampleCaptcha' => array(
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ),

);

> Load the BotDetect CakePHP component:

class ExampleController extends AppController { // your controller
  
  public $components = array(
    'BotDetect.Captcha' => array(
      'captchaConfig' => 'ExampleCaptcha'
    )
  );
}

Show a Captcha challenge in a View:

echo $this->Html->css(captcha_layout_stylesheet_url(), array('inline' => false));
  
// display Captcha markup, wrapped in an extra div for layout purposes
echo $this->Html->div('captcha', captcha_image_html(), false);

// Captcha code user input textbox
echo $this->Form->input('CaptchaCode');

3. Check User Input During Form Submission

When form is submitted, Captcha validation result must be checked in a Controller code:

if ($this->request->is('post')) {

  // validate the user-entered Captcha code
  $isHuman = captcha_validate($this->request->data['CaptchaCode']);

  // clear previous user input, since each Captcha code can only be validated once
  unset($this->request->data['CaptchaCode']);
 
  if ($isHuman) {
      // TODO: Captcha validation passed, perform protected action
  } else {
      // TODO: Captcha validation failed, show error message
  }
}

In-Depth CakePHP CAPTCHA Instructions and Explanations

Detailed CakePHP Captcha instructions and explanations can be found in the CakePHP 2 Captcha integration how to guide.

CodeIgniter 3
CodeIgniter 2.2

1. Copy CodeIgniter Captcha Library Files

Path Aliases Used Throughout This Guide

<MYCIAPP>: location of your working CodeIgniter application directory
<BDCIPACK>: the downloaded and extracted contents of the BotDetect Captcha CodeIgniter Package

Download the BotDetect Captcha CodeIgniter integration package and copy <BDCIPACK>/plugin/codeigniter-3/ libraries/botdetect
to:
<MYCIAPP>/application/libraries/botdetect
Copy:
<BDCIPACK>/plugin/codeigniter-3/ controllers/botdetect
to:
<MYCIAPP>/application/controllers/botdetect
Copy BotDetect PHP Captcha library from:
<BDCIPACK>/lib
to:
<MYCIAPP>/application/libraries/botdetect/lib

2. Show a Captcha Challenge on the Form

Register default route of the Captcha library:

$route['botdetect/captcha-handler'] = 'botdetect/captcha_handler/index';

Captcha configuration options (application/config/captcha.php):

<?php
// BotDetect PHP Captcha configuration options

$config = array(
  // Captcha configuration for example page
  'ExampleCaptcha' => array(
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ),

);

Load the BotDetect CodeIgniter library and generate the Captcha markup in your Controller:

public function index() // Your controller
{
  // load the BotDetect Captcha library and set its parameter
  $this->load->library('botdetect/BotDetectCaptcha', array(
    'captchaConfig' => 'ExampleCaptcha'
  ));

  // make Captcha Html accessible to View code
  $data['captchaHtml'] = $this->botdetectcaptcha->Html();

Show the Captcha challenge in the View:

  <link type="text/css" rel="Stylesheet" 
    href="<?php echo CaptchaUrls::LayoutStylesheetUrl() ?>" />
</head>
 
 […]
 
  <?php echo $captchaHtml; ?>
  <input type="text" name="CaptchaCode" id="CaptchaCode" value="" />

3. Check User Input During Form Submission

When the form is submitted, the Captcha validation result must be checked in Controller code:

if ($_POST) {
  // validate the user-entered Captcha code when the form is submitted
  $code = $this->input->post('CaptchaCode');
  $isHuman = $this->botdetectcaptcha->Validate($code);

  if (!$isHuman) {
    // TODO: Captcha validation failed, show error message
  } else {
    // TODO: Captcha validation passed, perform protected action
  }

In-Depth CodeIgniter CAPTCHA Instructions and Explanations

Detailed CodeIgniter Captcha instructions and explanations can be found in the CodeIgniter 3 Captcha integration how to guide.

1. Copy CodeIgniter Captcha Library Files

Path Aliases Used Throughout This Guide

<MYCIAPP>: location of your working CodeIgniter application directory
<BDCIPACK>: the downloaded and extracted contents of the BotDetect Captcha CodeIgniter Package

Download the BotDetect Captcha CodeIgniter integration package and copy <BDCIPACK>/plugin/codeigniter-2.2/ libraries/botdetect
to:
<MYCIAPP>/application/libraries/botdetect
Copy:
<BDCIPACK>/plugin/codeigniter-2.2/ controllers/botdetect
to:
<MYCIAPP>/application/controllers/botdetect
Copy BotDetect PHP Captcha library from:
<BDCIPACK>/lib
to:
<MYCIAPP>/application/libraries/botdetect/lib

2. Show a Captcha Challenge on the Form

Register default route of the Captcha library:

$route['botdetect/captcha-handler'] = 'botdetect/captcha_handler/index';

Captcha configuration options (application/config/captcha.php):

<?php
// BotDetect PHP Captcha configuration options

$config = array(
  // Captcha configuration for example page
  'ExampleCaptcha' => array(
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ),

);

Load the BotDetect CodeIgniter library and generate the Captcha markup in your Controller:

public function index() // Your controller
{
  // load the BotDetect Captcha library and set its parameter
  $this->load->library('botdetect/BotDetectCaptcha', array(
    'captchaConfig' => 'ExampleCaptcha'
  ));

  // make Captcha Html accessible to View code
  $data['captchaHtml'] = $this->botdetectcaptcha->Html();

Show the Captcha challenge in the View:

  <link type="text/css" rel="Stylesheet" 
    href="<?php echo CaptchaUrls::LayoutStylesheetUrl() ?>" />
</head>
 
 […]
 
  <?php echo $captchaHtml; ?>
  <input type="text" name="CaptchaCode" id="CaptchaCode" value="" />

3. Check User Input During Form Submission

When the form is submitted, the Captcha validation result must be checked in Controller code:

if ($_POST) {
  // validate the user-entered Captcha code when the form is submitted
  $code = $this->input->post('CaptchaCode');
  $isHuman = $this->botdetectcaptcha->Validate($code);

  if (!$isHuman) {
    // TODO: Captcha validation failed, show error message
  } else {
    // TODO: Captcha validation passed, perform protected action
  }

In-Depth CodeIgniter CAPTCHA Instructions and Explanations

Detailed CodeIgniter Captcha instructions and explanations can be found in the CodeIgniter 2.2 Captcha integration how to guide.

Laravel 5.7
Laravel 5.6
Laravel 5.5
Laravel 5.4
Laravel 5.3
Laravel 5.2
Laravel 5.1
Laravel 5.0
Laravel 4.2

1. Installing the BotDetect Laravel Captcha Composer Package

Step 1: Install the BotDetect Laravel Captcha Composer Package

Run the following command in your application's root directory:

Step 2: Register the Laravel Captcha service provider (<MY_LARAVEL_WEBROOT>/config/app.php):

"providers" => [
  ...
  LaravelCaptcha\Providers\LaravelCaptchaServiceProvider::class
]

2. Show a Captcha Challenge on the Form

a) If Laravel is a backend for your js-based frontend, perhaps you should start with a guide that describes integration from js-framework point of view: jQuery, Angular, AngularJS, or React.

b) If you are using Laravel forms, here is how to configure Captcha options, and display Captcha in your Laravel form:

Register GET and POST routes:

Route::get('example', 'ExampleController@getExample');
Route::post('example', 'ExampleController@postExample');

Captcha configuration options (/config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return [
  // Captcha configuration for example page
  'ExampleCaptcha' => [
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ],

];

Showing a Captcha challenge in a View:

<link href="{{ captcha_layout_stylesheet_url() }}" type="text/css" rel="stylesheet">
</head>
  
  [...]

  {!! captcha_image_html('ExampleCaptcha') !!}
  <input type="text" id="CaptchaCode" name="CaptchaCode">

3. Check User Input During Form Submission

When a form is submitted, Captcha validation result must be checked in a Controller code:

<?php namespace App\Http\Controllers;

use Illuminate\Http\Request;

class ExampleController extends Controller
{
  public function getExample()
  {
    return view('example');
  }

  public function postExample(Request $request)
  {
    // validate the user-entered Captcha code when the form is submitted
    $code = $request->input('CaptchaCode');
    $isHuman = captcha_validate($code);

    if ($isHuman) {
      // TODO: Captcha validation passed, perform protected  action
    } else {
      // TODO: Captcha validation failed, show error message
    }
  }
 
}

In-Depth Laravel CAPTCHA Instructions and Explanations

Detailed Laravel Captcha instructions and explanations can be found in the Laravel 5.7 Captcha integration how to guide.

1. Installing the BotDetect Laravel Captcha Composer Package

Step 1: Install the BotDetect Laravel Captcha Composer Package

Run the following command in your application's root directory:

Step 2: Register the Laravel Captcha service provider (<MY_LARAVEL_WEBROOT>/config/app.php):

"providers" => [
  ...
  LaravelCaptcha\Providers\LaravelCaptchaServiceProvider::class
]

2. Show a Captcha Challenge on the Form

a) If Laravel is a backend for your js-based frontend, perhaps you should start with a guide that describes integration from js-framework point of view: jQuery, Angular, AngularJS, or React.

b) If you are using Laravel forms, here is how to configure Captcha options, and display Captcha in your Laravel form:

Register GET and POST routes:

Route::get('example', 'ExampleController@getExample');
Route::post('example', 'ExampleController@postExample');

Captcha configuration options (/config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return [
  // Captcha configuration for example page
  'ExampleCaptcha' => [
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ],

];

Showing a Captcha challenge in a View:

<link href="{{ captcha_layout_stylesheet_url() }}" type="text/css" rel="stylesheet">
</head>
  
  [...]

  {!! captcha_image_html('ExampleCaptcha') !!}
  <input type="text" id="CaptchaCode" name="CaptchaCode">

3. Check User Input During Form Submission

When a form is submitted, Captcha validation result must be checked in a Controller code:

<?php namespace App\Http\Controllers;

use Illuminate\Http\Request;

class ExampleController extends Controller
{
  public function getExample()
  {
    return view('example');
  }

  public function postExample(Request $request)
  {
    // validate the user-entered Captcha code when the form is submitted
    $code = $request->input('CaptchaCode');
    $isHuman = captcha_validate($code);

    if ($isHuman) {
      // TODO: Captcha validation passed, perform protected  action
    } else {
      // TODO: Captcha validation failed, show error message
    }
  }
 
}

In-Depth Laravel CAPTCHA Instructions and Explanations

Detailed Laravel Captcha instructions and explanations can be found in the Laravel 5.6 Captcha integration how to guide.

1. Installing the BotDetect Laravel Captcha Composer Package

Step 1: Install the BotDetect Laravel Captcha Composer Package

Run the following command in your application's root directory:

Step 2: Register the Laravel Captcha service provider (<MY_LARAVEL_WEBROOT>/config/app.php):

"providers" => [
  ...
  LaravelCaptcha\Providers\LaravelCaptchaServiceProvider::class
]

2. Show a Captcha Challenge on the Form

a) If Laravel is a backend for your js-based frontend, perhaps you should start with a guide that describes integration from js-framework point of view: jQuery, Angular, AngularJS, or React.

b) If you are using Laravel forms, here is how to configure Captcha options, and display Captcha in your Laravel form:

Register GET and POST routes:

Route::get('example', 'ExampleController@getExample');
Route::post('example', 'ExampleController@postExample');

Captcha configuration options (/config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return [
  // Captcha configuration for example page
  'ExampleCaptcha' => [
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ],

];

Showing a Captcha challenge in a View:

<link href="{{ captcha_layout_stylesheet_url() }}" type="text/css" rel="stylesheet">
</head>
  
  [...]

  {!! captcha_image_html('ExampleCaptcha') !!}
  <input type="text" id="CaptchaCode" name="CaptchaCode">

3. Check User Input During Form Submission

When a form is submitted, Captcha validation result must be checked in a Controller code:

<?php namespace App\Http\Controllers;

use Illuminate\Http\Request;

class ExampleController extends Controller
{
  public function getExample()
  {
    return view('example');
  }

  public function postExample(Request $request)
  {
    // validate the user-entered Captcha code when the form is submitted
    $code = $request->input('CaptchaCode');
    $isHuman = captcha_validate($code);

    if ($isHuman) {
      // TODO: Captcha validation passed, perform protected  action
    } else {
      // TODO: Captcha validation failed, show error message
    }
  }
 
}

In-Depth Laravel CAPTCHA Instructions and Explanations

Detailed Laravel Captcha instructions and explanations can be found in the Laravel 5.5 Captcha integration how to guide.

1. Installing the BotDetect Laravel Captcha Composer Package

Step 1: Install the BotDetect Laravel Captcha Composer Package

Run the following command in your application's root directory:

Step 2: Register the Laravel Captcha service provider (<MY_LARAVEL_WEBROOT>/config/app.php):

"providers" => [
  ...
  LaravelCaptcha\Providers\LaravelCaptchaServiceProvider::class
]

2. Show a Captcha Challenge on the Form

a) If Laravel is a backend for your js-based frontend, perhaps you should start with a guide that describes integration from js-framework point of view: jQuery, Angular, AngularJS, or React.

b) If you are using Laravel forms, here is how to configure Captcha options, and display Captcha in your Laravel form:

Register GET and POST routes:

Route::get('example', 'ExampleController@getExample');
Route::post('example', 'ExampleController@postExample');

Captcha configuration options (/config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return [
  // Captcha configuration for example page
  'ExampleCaptcha' => [
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ],

];

Showing a Captcha challenge in a View:

<link href="{{ captcha_layout_stylesheet_url() }}" type="text/css" rel="stylesheet">
</head>
  
  [...]

  {!! captcha_image_html('ExampleCaptcha') !!}
  <input type="text" id="CaptchaCode" name="CaptchaCode">

3. Check User Input During Form Submission

When a form is submitted, Captcha validation result must be checked in a Controller code:

<?php namespace App\Http\Controllers;

use Illuminate\Http\Request;

class ExampleController extends Controller
{
  public function getExample()
  {
    return view('example');
  }

  public function postExample(Request $request)
  {
    // validate the user-entered Captcha code when the form is submitted
    $code = $request->input('CaptchaCode');
    $isHuman = captcha_validate($code);

    if ($isHuman) {
      // TODO: Captcha validation passed, perform protected  action
    } else {
      // TODO: Captcha validation failed, show error message
    }
  }
 
}

In-Depth Laravel CAPTCHA Instructions and Explanations

Detailed Laravel Captcha instructions and explanations can be found in the Laravel 5.4 Captcha integration how to guide.

1. Installing the BotDetect Laravel Captcha Composer Package

Step 1: Install the BotDetect Laravel Captcha Composer Package

Run the following command in your application's root directory:

Step 2: Register the Laravel Captcha service provider (<MY_LARAVEL_WEBROOT>/config/app.php):

"providers" => [
  ...
  LaravelCaptcha\Providers\LaravelCaptchaServiceProvider::class
]

2. Show a Captcha Challenge on the Form

a) If Laravel is a backend for your js-based frontend, perhaps you should start with a guide that describes integration from js-framework point of view: jQuery, Angular, AngularJS, or React.

b) If you are using Laravel forms, here is how to configure Captcha options, and display Captcha in your Laravel form:

Register GET and POST routes:

Route::get('example', 'ExampleController@getExample');
Route::post('example', 'ExampleController@postExample');

Captcha configuration options (/config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return [
  // Captcha configuration for example page
  'ExampleCaptcha' => [
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ],

];

Showing a Captcha challenge in a View:

<link href="{{ captcha_layout_stylesheet_url() }}" type="text/css" rel="stylesheet">
</head>
  
  [...]

  {!! captcha_image_html('ExampleCaptcha') !!}
  <input type="text" id="CaptchaCode" name="CaptchaCode">

3. Check User Input During Form Submission

When a form is submitted, Captcha validation result must be checked in a Controller code:

<?php namespace App\Http\Controllers;

use Illuminate\Http\Request;

class ExampleController extends Controller
{
  public function getExample()
  {
    return view('example');
  }

  public function postExample(Request $request)
  {
    // validate the user-entered Captcha code when the form is submitted
    $code = $request->input('CaptchaCode');
    $isHuman = captcha_validate($code);

    if ($isHuman) {
      // TODO: Captcha validation passed, perform protected  action
    } else {
      // TODO: Captcha validation failed, show error message
    }
  }
 
}

In-Depth Laravel CAPTCHA Instructions and Explanations

Detailed Laravel Captcha instructions and explanations can be found in the Laravel 5.3 Captcha integration how to guide.

1. Installing the BotDetect Laravel Captcha Composer Package

Step 1: Install the BotDetect Laravel Captcha Composer Package

Run the following command in your application's root directory:

Step 2: Register the Laravel Captcha service provider (<MY_LARAVEL_WEBROOT>/config/app.php):

"providers" => [
  ...
  LaravelCaptcha\Providers\LaravelCaptchaServiceProvider::class
]

Step 3: Publish Captcha configuration file:

Run the following command in your application's root directory:

The captcha.php file is already put in Laravel's config folder now.

2. Show a Captcha Challenge on the Form

Register GET and POST routes:

Route::group(['middleware' => 'web'], function () {
  Route::get('example', 'ExampleController@getExample');
  Route::post('example', 'ExampleController@postExample');
});

Captcha configuration options (/config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return [
  // Captcha configuration for example page
  'ExampleCaptcha' => [
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ],

];

Showing a Captcha challenge in a View:

<link href="{{ captcha_layout_stylesheet_url() }}" type="text/css" rel="stylesheet">
</head>
  
  [...]

  {!! captcha_image_html('ExampleCaptcha') !!}
  <input type="text" id="CaptchaCode" name="CaptchaCode">

3. Check User Input During Form Submission

When a form is submitted, Captcha validation result must be checked in a Controller code:

<?php namespace App\Http\Controllers;

use Illuminate\Http\Request;

class ExampleController extends Controller
{
  public function getExample()
  {
    return view('example');
  }

  public function postExample(Request $request)
  {
    // validate the user-entered Captcha code when the form is submitted
    $code = $request->input('CaptchaCode');
    $isHuman = captcha_validate($code);

    if ($isHuman) {
      // TODO: Captcha validation passed, perform protected  action
    } else {
      // TODO: Captcha validation failed, show error message
    }
  }
 
}

In-Depth Laravel CAPTCHA Instructions and Explanations

Detailed Laravel Captcha instructions and explanations can be found in the Laravel 5.2 Captcha integration how to guide.

1. Installing the BotDetect Laravel Captcha Composer Package

Step 1: Install the BotDetect Laravel Captcha Composer Package

Run the following command in your application's root directory:

Step 2: Register the Laravel Captcha service provider (<MY_LARAVEL_WEBROOT>/config/app.php):

"providers" => [
  ...
  LaravelCaptcha\Providers\LaravelCaptchaServiceProvider::class
]

Step 3: Publish Captcha configuration file:

Run the following command in your application's root directory:

The captcha.php file is already put in Laravel's config folder now.

2. Show a Captcha Challenge on the Form

Register GET and POST routes:

Route::get('example', 'ExampleController@getExample');
Route::post('example', 'ExampleController@postExample');

Captcha configuration options (/config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return [
  // Captcha configuration for example page
  'ExampleCaptcha' => [
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ],

];

Showing a Captcha challenge in a View:

<link href="{{ captcha_layout_stylesheet_url() }}" type="text/css" rel="stylesheet">
</head>
  
  [...]

  {!! captcha_image_html('ExampleCaptcha') !!}
  <input type="text" id="CaptchaCode" name="CaptchaCode">

3. Check User Input During Form Submission

When a form is submitted, Captcha validation result must be checked in a Controller code:

<?php namespace App\Http\Controllers;

use Illuminate\Http\Request;

class ExampleController extends Controller
{
  public function getExample()
  {
    return view('example');
  }

  public function postExample(Request $request)
  {
    // validate the user-entered Captcha code when the form is submitted
    $code = $request->input('CaptchaCode');
    $isHuman = captcha_validate($code);

    if ($isHuman) {
      // TODO: Captcha validation passed, perform protected  action
    } else {
      // TODO: Captcha validation failed, show error message
    }
  }
 
}

In-Depth Laravel CAPTCHA Instructions and Explanations

Detailed Laravel Captcha instructions and explanations can be found in the Laravel 5.1 Captcha integration how to guide.

1. Installing the BotDetect Laravel Captcha Composer Package

Step 1: Install the BotDetect Laravel Captcha Composer Package

Run the following command in your application's root directory:

Step 2: Register the Laravel Captcha service provider (<MY_LARAVEL_WEBROOT>/config/app.php):

"providers" => [
  ...
  "LaravelCaptcha\Providers\LaravelCaptchaServiceProvider"
]

Step 3: Publish Captcha configuration file:

Run the following command in your application's root directory:

The captcha.php file is already put in Laravel's config folder now.

2. Show a Captcha Challenge on the Form

Register GET and POST routes:

Route::get('example', 'ExampleController@getExample');
Route::post('example', 'ExampleController@postExample');

Captcha configuration options (/config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return [
  // Captcha configuration for example page
  'ExampleCaptcha' => [
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ],

];

Showing a Captcha challenge in a View:

<link href="{{ captcha_layout_stylesheet_url() }}" type="text/css" rel="stylesheet">
</head>
  
  [...]

  {!! captcha_image_html('ExampleCaptcha') !!}
  <input type="text" id="CaptchaCode" name="CaptchaCode">

3. Check User Input During Form Submission

When a form is submitted, Captcha validation result must be checked in a Controller code:

<?php namespace App\Http\Controllers;

use Illuminate\Http\Request;

class ExampleController extends Controller
{
  public function getExample()
  {
    return view('example');
  }

  public function postExample(Request $request)
  {
    // validate the user-entered Captcha code when the form is submitted
    $code = $request->input('CaptchaCode');
    $isHuman = captcha_validate($code);

    if ($isHuman) {
      // TODO: Captcha validation passed, perform protected  action
    } else {
      // TODO: Captcha validation failed, show error message
    }
  }
 
}

In-Depth Laravel CAPTCHA Instructions and Explanations

Detailed Laravel Captcha instructions and explanations can be found in the Laravel 5.0 Captcha integration how to guide.

1. Installing the BotDetect Laravel Captcha Composer Package

Step 1: Install the BotDetect Laravel Captcha Composer Package

Run the following command in your application's root directory:

Step 2: Register the Laravel Captcha service provider (<MY_LARAVEL_APP>/config/app.php):

"providers" => array(
  ...
  "LaravelCaptcha\Providers\LaravelCaptchaServiceProvider"
)

2. Show a Captcha Challenge on the Form

Register GET and POST routes:

Route::get('example', 'ExampleController@getExample');
Route::post('example', 'ExampleController@postExample');

Captcha configuration options (/app/config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return array(
  // Captcha configuration for example page
  'ExampleCaptcha' => array(
    'UserInputID' => 'CaptchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ),

);

Showing a Captcha challenge in a View:

  {{ HTML::style(captcha_layout_stylesheet_url()) }}
</head>

  [...]

   {{ captcha_image_html('ExampleCaptcha') }}
  {{ Form::text('CaptchaCode', null, array('id' => 'CaptchaCode')) }}

3. Check User Input During Form Submission

When a form is submitted, Captcha validation result must be checked in a Controller code:

<?php

class ExampleController extends BaseController {

  public function getExample() {
    return View::make('example');
  }

  public function postExample() {
    // validate the user-entered Captcha code when the form is submitted
    $code = Input::get('CaptchaCode');
    $isHuman = captcha_validate($code);

    if ($isHuman) {
      // TODO: Captcha validation passed, perform protected  action
    } else {
      // TODO: Captcha validation failed, show error message
    }
  }

}

In-Depth Laravel CAPTCHA Instructions and Explanations

Detailed Laravel Captcha instructions and explanations can be found in the Laravel 4.2 Captcha integration how to guide.

Symfony 4
Symfony 3
Symfony 2

1. Installing the BotDetect Symfony CaptchaBundle

Step 1: Download CaptchaBundle using composer

Run the following command in your application's root directory:

Step 2: Import CaptchaBundle routing file (config/routes.yml):

captcha_routing:
  resource: "@CaptchaBundle/Resources/config/routing.yml"

2. Show a Captcha Challenge on the Form

Captcha configuration options (config/packages/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return [
  // Captcha configuration for example page
  'ExampleCaptcha' => [
    'UserInputID' => 'captchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ],

];

Adding the CaptchaType in your form:

use Captcha\Bundle\CaptchaBundle\Form\Type\CaptchaType;

$builder->add('captchaCode', CaptchaType::class, array(
  'captchaConfig' => 'ExampleCaptcha'
));

3. Check User Input During Form Submission

Using the ValidCaptcha constraint to validate captcha code when a form is submitted:

namespace App\Entity;

use Captcha\Bundle\CaptchaBundle\Validator\Constraints as CaptchaAssert;

class Example
{
  /**
   * @CaptchaAssert\ValidCaptcha(
   *      message = "CAPTCHA validation failed, try again."
   * )
   */
  protected $captchaCode;

  public function getCaptchaCode()
  {
    return $this->captchaCode;
  }

  public function setCaptchaCode($captchaCode)
  {
    $this->captchaCode = $captchaCode;
  }
}

In-Depth Symfony CAPTCHA Instructions and Explanations

Detailed Symfony Captcha instructions and explanations can be found in the Symfony 4 Captcha integration how to guide.

1. Installing the BotDetect Symfony CaptchaBundle

Step 1: Download CaptchaBundle using composer

Run the following command in your application's root directory:

Step 2: Enable the bundle (app/AppKernel.php):

$bundles = array(
  ...
  new Captcha\Bundle\CaptchaBundle\CaptchaBundle(),
);

Step 3: Import CaptchaBundle routing file (app/config/routing.yml):

captcha_routing:
  resource: "@CaptchaBundle/Resources/config/routing.yml"

2. Show a Captcha Challenge on the Form

Captcha configuration options (app/config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return [
  // Captcha configuration for example page
  'ExampleCaptcha' => [
    'UserInputID' => 'captchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ],

];

Adding the CaptchaType in your form:

$builder->add('captchaCode', 'Captcha\Bundle\CaptchaBundle\Form\Type\CaptchaType', array(
  'captchaConfig' => 'ExampleCaptcha'
));

3. Check User Input During Form Submission

Using the ValidCaptcha constraint to validate captcha code when a form is submitted:

namespace AppBundle\Entity;

use Captcha\Bundle\CaptchaBundle\Validator\Constraints as CaptchaAssert;

class Example
{
  /**
   * @CaptchaAssert\ValidCaptcha(
   *      message = "CAPTCHA validation failed, try again."
   * )
   */
  protected $captchaCode;

  public function getCaptchaCode()
  {
    return $this->captchaCode;
  }

  public function setCaptchaCode($captchaCode)
  {
    $this->captchaCode = $captchaCode;
  }
}

In-Depth Symfony CAPTCHA Instructions and Explanations

Detailed Symfony Captcha instructions and explanations can be found in the Symfony 3 Captcha integration how to guide.

1. Installing the BotDetect Symfony CaptchaBundle

Step 1: Download CaptchaBundle using composer

Run the following command in your application's root directory:

Step 2: Enable the bundle (app/AppKernel.php):

$bundles = array(
  ...
  new Captcha\Bundle\CaptchaBundle\CaptchaBundle(),
);

Step 3: Import CaptchaBundle routing file (app/config/routing.yml):

captcha_routing:
  resource: "@CaptchaBundle/Resources/config/routing.yml"

2. Show a Captcha Challenge on the Form

Captcha configuration options (app/config/captcha.php):

<?php if (!class_exists('CaptchaConfiguration')) { return; }

// BotDetect PHP Captcha configuration options

return [
  // Captcha configuration for example page
  'ExampleCaptcha' => [
    'UserInputID' => 'captchaCode',
    'ImageWidth' => 250,
    'ImageHeight' => 50,
  ],

];

Adding the captcha field type in your form:

$builder->add('captchaCode', 'captcha', array(
  'captchaConfig' => 'ExampleCaptcha'
));

3. Check User Input During Form Submission

Using the ValidCaptcha constraint to validate captcha code when a form is submitted:

namespace AppBundle\Entity;

use Captcha\Bundle\CaptchaBundle\Validator\Constraints as CaptchaAssert;

class Example
{
  /**
   * @CaptchaAssert\ValidCaptcha(
   *      message = "CAPTCHA validation failed, try again."
   * )
   */
  protected $captchaCode;

  public function getCaptchaCode()
  {
    return $this->captchaCode;
  }

  public function setCaptchaCode($captchaCode)
  {
    $this->captchaCode = $captchaCode;
  }
}

In-Depth Symfony CAPTCHA Instructions and Explanations

Detailed Symfony Captcha instructions and explanations can be found in the Symfony2 Captcha integration how to guide.

BotDetect PHP CAPTCHA Free Version

You can download BotDetect PHP CAPTCHA Library for free and use it immediately! Your PHP forms can be protected from spam (and bots in general) in minutes.

We offer basic email support for free to all BotDetect users. So if you need any assistance integrating BotDetect or have any questions or feedback, our Support department is at your disposal.

Once the BotDetect Captcha generator library has been integrated into your PHP website and you're satisfied with how it works, it's easy to upgrade your license if you need the extra features offered by commercial BotDetect versions.

BotDetect PHP CAPTCHA Free Download

BotDetect PHP CAPTCHA System Requirements

OS	Server	PHP	Browser
Supported Operating Systems: Linux Windows Mac OS X	Supported Web Servers: Apache 2.2+	Supported PHP Versions: PHP 7.3.0+ PHP 7.2.0+ PHP 7.1.0+ PHP 7.0.0+ PHP 5.7.0+ PHP 5.6.0+ PHP 5.5.0+ PHP 5.4.0+ PHP 5.3.2+ PHP installation must include libgd and SQLite3 support.	Officially Supported Browsers*: Chrome 49+ Edge 20+ Firefox 52+ IE 8+ Opera 36+ Safari (OSX) 5+ Safari (iOS 6+) Numerous other browsers are not officially supported but the captcha still works. Read the notes below!

OS

Server

PHP

Browser

Supported Operating Systems:

Linux
Windows
Mac OS X

Supported Web Servers:

Apache 2.2+

Supported PHP Versions:

PHP 7.3.0+
PHP 7.2.0+
PHP 7.1.0+
PHP 7.0.0+
PHP 5.7.0+
PHP 5.6.0+
PHP 5.5.0+
PHP 5.4.0+
PHP 5.3.2+

PHP installation must include libgd and SQLite3 support.

Officially Supported Browsers*:

Chrome 49+
Edge 20+
Firefox 52+
IE 8+
Opera 36+
Safari (OSX) 5+
Safari (iOS 6+)

Numerous other browsers are not officially supported but the captcha still works.

Read the notes below!

*

'Officially Supported Browsers' are those browsers for which we do the testing in order to ensure that both the image and audio captcha options are working properly.

Nonetheless, both the image and audio captcha options are working properly in the most of non-archaic ** browsers anyway -- officially-supported, or not -- while the image captcha option alone works in all of them!

If you find our 'Officially Supported Browsers' policy too-restrictive check Recaptcha the Stalker's one that says:

We support the two most recent major versions of the following:
- desktop (Windows, Linux, Mac): Chrome, Firefox, Safari, IE
- mobile: Chrome, Safari, Android native browser (4.0+)

We guess that after checking the Recaptcha's policy -- you will consider ours as the accommodative one :).

**

Archaic browsers?

At present, our 'Archaic Browsers' policy works this way:

Those last remaining few real humans still browsing around using the WinXP should update their browsers to the latest version that still works on the XP.

Or, in the less nice words:

If those last remaining few laggards cannot be bothered to update their browsers -- we cannot be bothered neither -- nor you should be!
Half of the Internet is broken for them since years ago anyway -- and they do not seem to care!

Current BotDetect Versions

BotDetect ASP.NET CAPTCHA

2019-07-22

v4.4.2
BotDetect Java CAPTCHA

2019-07-22

v4.0.Beta3.7
BotDetect PHP CAPTCHA

2019-07-22

v4.2.5

BotDetect Captcha Image Samples

More CAPTCHA image samples...

BotDetect Audio Captcha Sound Samples

More audio CAPTCHA sound samples...

BotDetect PHP CAPTCHA Generator

PHP CAPTCHA Generator Highlights:

Quickstarts:

1. Copy Captcha Library Files

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth PHP CAPTCHA Instructions and Explanations

1. Installing the BotDetect CakePHP Captcha Composer Plugin

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth CakePHP CAPTCHA Instructions and Explanations

1. Copy CakePHP Captcha Plugin Files

Path Aliases Used Throughout This Guide

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth CakePHP CAPTCHA Instructions and Explanations

1. Copy CodeIgniter Captcha Library Files

Path Aliases Used Throughout This Guide

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth CodeIgniter CAPTCHA Instructions and Explanations

1. Copy CodeIgniter Captcha Library Files

Path Aliases Used Throughout This Guide

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth CodeIgniter CAPTCHA Instructions and Explanations

1. Installing the BotDetect Laravel Captcha Composer Package

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth Laravel CAPTCHA Instructions and Explanations

1. Installing the BotDetect Laravel Captcha Composer Package

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth Laravel CAPTCHA Instructions and Explanations

1. Installing the BotDetect Laravel Captcha Composer Package

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth Laravel CAPTCHA Instructions and Explanations

1. Installing the BotDetect Laravel Captcha Composer Package

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth Laravel CAPTCHA Instructions and Explanations

1. Installing the BotDetect Laravel Captcha Composer Package

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth Laravel CAPTCHA Instructions and Explanations

1. Installing the BotDetect Laravel Captcha Composer Package

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth Laravel CAPTCHA Instructions and Explanations

1. Installing the BotDetect Laravel Captcha Composer Package

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth Laravel CAPTCHA Instructions and Explanations

1. Installing the BotDetect Laravel Captcha Composer Package

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth Laravel CAPTCHA Instructions and Explanations

1. Installing the BotDetect Laravel Captcha Composer Package

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth Laravel CAPTCHA Instructions and Explanations

1. Installing the BotDetect Symfony CaptchaBundle

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth Symfony CAPTCHA Instructions and Explanations

1. Installing the BotDetect Symfony CaptchaBundle

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth Symfony CAPTCHA Instructions and Explanations

1. Installing the BotDetect Symfony CaptchaBundle

2. Show a Captcha Challenge on the Form

3. Check User Input During Form Submission

In-Depth Symfony CAPTCHA Instructions and Explanations

BotDetect PHP CAPTCHA Free Version

BotDetect PHP CAPTCHA System Requirements

Current BotDetect Versions

Popular Content

BotDetect Captcha Image Samples

BotDetect Audio Captcha Sound Samples