How to Validate Google reCaptcha on Form Submit

php html recaptcha
Drew Kennedy picture Drew Kennedy · Dec 12, 2014 · Viewed 126.3k times · Source

Recently, Google completely overhauled their reCaptcha API and simplified it to a single checkbox.

reCaptcha

The problem is, I can submit a form with the reCaptcha included without checking it and the form will ignore the reCaptcha.

Before you had to send the form to a PHP file with the private key et al, but I'm not seeing any mention of that in their Developer's Guide. I have no idea how to validate the form to be sure the new reCaptcha was filled by the user.

Am I missing something? Is that PHP file with the private key still required?

All I have for the reCaptcha so far is:

<div data-type="image" class="g-recaptcha" data-sitekey="My Public Key"></div>

Answer

Ali Bassam picture Ali Bassam · Dec 15, 2014

If you want to check if the User clicked on the I'm not a robot checkbox, you can use the .getResponse() function provided by the reCaptcha API.

It will return an empty string in case the User did not validate himself, something like this:

if (grecaptcha.getResponse() == ""){
    alert("You can't proceed!");
} else {
    alert("Thank you");
}

In case the User has validated himself, the response will be a very long string.

More about the API can be found on this page: reCaptcha Javascript API

Related questions

Google reCaptcha response "Uncaught (in promise) null"

I'm use reCaptcha v2 but in dev console response Uncaught (in promise) null in in any case (and moving the .reset() function) console: my code for recaptcha: <div class="text-xs-center" style="text-align: center; height:150px;"> <p style="…

Read More
How to call a PHP function on the click of a button

I have created a page called functioncalling.php that contains two buttons, Submit and Insert. I want to test which function is executed when a button gets clicked. I want the output to appear on the same page. So, I …

Read More
How to set HTTP header to UTF-8 using PHP which is valid in W3C validator?

I have several PHP pages echoing out various things into HTML pages with the following code. <meta http-equiv="Content-type" content="text/html; charset=utf-8" /> However, when I validate using the W3C validator it comes up with: The …

Read More