How to Integrate Google reCAPTCHA

Last updated on March 28, 2018

In this post, I would like to show you how to integrate Google reCAPTCHA. Google reCAPTCHA is more user-friendly and reliable which protects your websites form spams and robots.

What is reCAPTCHA?

If Google feels that you are not human, it will give the second prompt and it will ask you to fill the captcha. Once you verify that it lets you access the resource.

How to integrate?

Integrate Google reCAPTCHA you need followings.

• A Gmail account. If not, please create it for you.
• Basic Knowledge of HTML, JavaScript and also PHP

Below are the simple steps to integrate reCAPTCHA…

Step 1:
Get the API key by visit this link https://www.google.com/recaptcha/admin

Client-side Integration: Step 2:
Underneath these keys, there are some scripts that will be added to the client side. You can also define the language for reCaptcha.English is default language. Add the script line at footer or just below the form.

Paste this snippet before the closing tag on your HTML template:

Paste this snippet at the end of the

    

 
   
  
  

    Email address
    
  
  

    Message
    
  

 

  



  Submit



  

To ensure that reCAPTCHA is working properly, we will run some server-side checks. Save this file as contact.php (If you want to use different name dont fogot to update form action).

 'YOUR-GOOGLE-RECAPTCHA-SECREAT-KEY', // Secret key
    'response' => $contact_form_reqeust['g-recaptcha-response'],
    'remoteip' => get_user_ip()
];

$response = curl_post('https://www.google.com/recaptcha/api/siteverify',$payload);

$response = json_decode($response);

if($response->success) {
    // print_r($contact_form_reqeust)
    echo 'valid request';
} else {
    echo 'invalid request';
}

function curl_post($url, $payload) {
    // initiate cURL resource
    $ch = curl_init();    
    curl_setopt($ch, CURLOPT_URL,$url);
    // tell curl you want to post something
    curl_setopt($ch, CURLOPT_POST, true);  
    // define what you want to post
    curl_setopt($ch, CURLOPT_POSTFIELDS, $payload);
    // return the output in string format
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    // execute post
    $output = curl_exec ($ch);
    // close the connection to free up memory
    curl_close ($ch);

    return $output;
}

function get_user_ip() {
    if (isset($_SERVER['HTTP_CLIENT_IP']))
         $ipaddress = $_SERVER['HTTP_CLIENT_IP'];
     else if(isset($_SERVER['HTTP_X_FORWARDED_FOR']))
         $ipaddress = $_SERVER['HTTP_X_FORWARDED_FOR'];
     else if(isset($_SERVER['HTTP_X_FORWARDED']))
         $ipaddress = $_SERVER['HTTP_X_FORWARDED'];
     else if(isset($_SERVER['HTTP_FORWARDED_FOR']))
         $ipaddress = $_SERVER['HTTP_FORWARDED_FOR'];
     else if(isset($_SERVER['HTTP_FORWARDED']))
         $ipaddress = $_SERVER['HTTP_FORWARDED'];
     else if(isset($_SERVER['REMOTE_ADDR']))
         $ipaddress = $_SERVER['REMOTE_ADDR'];
     else
         $ipaddress = 'UNKNOWN';
 
     return $ipaddress; 
}