Step 1: Register your website on Google reCAPTCHA
To start the process, you need to register your website on Google reCAPTCHA. Go to https://www.google.com/recaptcha/admin and add your website.
You will be returned a set of keys like something below.
Site key Use this in the HTML code your site serves to users. 6Lc4-XXXXXXXXXX-XXXXXXXXXX Secret key Use this for communication between your site and Google. Be sure to keep it a secret. 6Lc4-YYYYYYYYYY-YYYYYYYYYY
Step 2: Adding the code to your website
<?php $site_key = "6Lc4-XXXXXXXXXX-XXXXXXXXXX"; $recaptcha_secret = "6Lc4-YYYYYYYYYY-YYYYYYYYYY"; ?> <html> <head> <title>Google reCAPTCHA Demo</title> </head> <body> <form method="post" action="index.php"> Enter your website: <input type="text" name="website" id="website" placeholder="https://www.shounakgupte.com" required /> <input type="submit" value="Submit"> <div class="g-recaptcha" data-sitekey="<?php echo $site_key; ?>"></div> </form> <script src='https://www.google.com/recaptcha/api.js'></script> </body> </html> <?php if($_REQUEST['website']){ //verify captcha $response = file_get_contents("https://www.google.com/recaptcha/api/siteverify?secret=".$recaptcha_secret."&response=".$_POST['g-recaptcha-response']); $response = json_decode($response, true); if($response["success"] === true) { //not a robot } else { //you are a robot } }