Quick Example of using Google's reCaptcha (v2) in PHP

Quick Example of using Google's reCaptcha (v2) in PHP

Quick example for PHP in implementing reCaptcha (v2)

Users get the following checkbox; If google isn't sure when checked, they prompt with photo tiles, to identify things like traffic lights, etc.

 

Step 1: Go to Google and setup your website to get your keys

https://www.google.com/recaptcha/

 

Step 2: Get your keys from Google

  • Go to your admin console from the site above.
  • Select your website (from the above step 1)
  • Copy your keys as shown below

 

Step 3: Create your HTML form for posting

  • Create the form you wish to use for this plugin.
  • In that PAGE (<head>), you will need to call the Google Captcha library.  
    • <script src="https://www.google.com/recaptcha/api.js" async defer></script>
  • Inside the FORM, place the follwing code: 
    • <div class="g-recaptcha" data-sitekey="YOUR_SITE_KEY"></div>
  • Optional: If you want to test to see if user checked the reCaptcha in jQuery:
<script>
$('#your-form-id').submit( function() {
     if($('#g-recaptcha-response').val() == '') {
          alert('Please check the "I\'m not a robot" reCAPTCHA box.');
​          return false;
   }
​});
</script>


Step 4: Post to the Google API and find success or failure.  See the PHP example function below.

Use the following function to check Google's response to the posted-checked results from the visitor.

$gRecaptchaResponse = $_POST['g-recaptcha-response']);

$result = checkReCaptcha($gRecaptchaResponse);
var_dump($result);

function checkReCaptcha($gRecaptchaResponse) {

        $url = 'https://www.google.com/recaptcha/api/siteverify'; // Post to google

        $postdata = http_build_query(
            ["secret"=>"Your_Google_Secret_Key",
                "response"=>$gRecaptchaResponse, //response-field generated from user-not-robot-click
                "remoteip"=>$_SERVER['REMOTE_ADDR'] //optional
            ]);
        $postsettings = ['http' =>
            [
                'method'  => 'POST',
                'header'  => 'Content-type: application/x-www-form-urlencoded',
                'content' => $postdata
            ]
        ];
        $context  = stream_context_create($postsettings);
        $result = file_get_contents($url, false, $context);
        $result = json_decode($result);

        return $result;
    }

 

 

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mike knebel

Software Developer - Websites, Mobile Apps. Owner of Logistics Logic, 307WEB and 405Software
@mknebel   MikeKnebel