Google ReCaptcha not posting 'g-recaptcha-response' on SOME pages - php

Question

I have been having this issue for a while and I cant figure it out. My Google recaptcha code seems to work on some websites - but the exact same code when added to other websites (or even other pages within the same website) won't work.
When it doesn't work, if I do a var_dump($_POST['g-recaptcha-response']); (on the second page) I get NULL.
My initial/form code:
<script src='https://www.google.com/recaptcha/api.js'></script>
<div class="g-recaptcha" data-sitekey="xxxxx"></div>
My verification page code:
$gRecaptcha = $_POST['g-recaptcha-response'];
$response=file_get_contents("https://www.google.com/recaptcha/api/siteverify?secret=xxxxx&response=".$gRecaptcha."&remoteip=".$_SERVER['REMOTE_ADDR']);
if($response.success==false || !$gRecaptcha){
die('xxxx');
}
There are other's that posted this question as well, but it doesn't seem any of them have a solution posted (they all just switched to a different captcha).
Any suggestions what to check next?

Answer 1

Your condition inside if clause is wrong. The API response is a json object, like this:
{
"success": true|false,
"challenge_ts": timestamp, // timestamp of the challenge load (ISO format yyyy-MM-dd'T'HH:mm:ssZZ)
"hostname": string, // the hostname of the site where the reCAPTCHA was solved
"error-codes": [...] // optional
}
Here's the reference:
Verifying the user's response
So first you have to decode it using json_decode() function and then check the status of user's response.
Hence your code should be like this:
if(isset($_POST['g-recaptcha-response']) && !empty($_POST['g-recaptcha-response'])){
//get verified response data
//your site secret key
$secret = 'YOUR_SECRET_KEY';
$gRecaptcha = $_POST['g-recaptcha-response'];
$gRecaptcha = "https://www.google.com/recaptcha/api/siteverify?secret=".$secret."&response=".$_POST['g-recaptcha-response'];
$response = file_get_contents($gRecaptcha);
$responseData = json_decode($response);
if($responseData->success){
// success
}else{
// failure
}
}

Answer 2

Use like this:
Step 1 :
put this code for validate :
<?php
$secret = "Your own code";
$sitekey = "Your own code";
if ($_SERVER['REQUEST_METHOD'] == 'POST'){
$captcha=$_POST['g-recaptcha-response'];
if(!$captcha){
header("Location: index.php?info=cap");
exit;
}
$response=json_decode(file_get_contents("https://www.google.com/recaptcha/api/siteverify?secret=".$secret."&response=".$captcha."&remoteip=".$_SERVER['REMOTE_ADDR']), true);
if($response['success'] == false)
{
header("Location: index.php?info=cap");
exit;
}
}
?>
Step 2 : use this tag in your form :
<label>I'm not robot: </label>
<div class="g-recaptcha"></div>
Step 3 : Google API
<script src="https://www.google.com/recaptcha/api.js?onload=CaptchaCallback&render=explicit" async defer></script>
<script type="text/javascript">
var CaptchaCallback = function(){
$('.g-recaptcha').each(function(index, el) {
grecaptcha.render(el, {'sitekey' : '<?php echo $sitekey;?>'});
});
};
</script>

Answer 3

Verify you have added both of these in google recaptcha:
www.yourdomain.com and yourdomain.com