BotDetect CAPTCHA Crash Course

On this page we demonstrate how easy is to integrate BotDetect Captcha in your forms.

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

1. Copy Captcha Library Files

Copy BotDetect.php and the BotDetect folder to your application. These files (and a sample project made by following these instructions, named "Basic CAPTCHA sample") are included in the BotDetect installation.

2. Show a Captcha Challenge on the Form

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

<?php session_start(); ?>

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

  <?php require("BotDetect.php"); ?>
</head>

  […]

<?php // Adding BotDetect Captcha to the page 
  $SampleCaptcha = new Captcha("SampleCaptcha");
  $SampleCaptcha->UserInputID = "CaptchaCode";
  echo $SampleCaptcha->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 = $SampleCaptcha->Validate();
    
    if (!$isHuman) {
      // TODO: Captcha validation failed, show error message
    } else {
      // TODO: Captcha validation passed, perform protected action
    } 
  }
?>

BotDetect CAPTCHA Options

To find more about configuring BotDetect and integrating it in various usage scenarios, please check the getting started with BotDetect Captcha page.