CODE EXAMPLE FOR PHP

google recaptcha varification in php codeigniter

/**
	 * VALIDATE RECAPTHCA FUNCTION IS RESPONSIBLE FOR VALIDATING THE REACAPTCHA
	 *
	 * @return boolean
	 */
	function validate_captcha()
	{
		$recaptcha = trim($this->input->post('g-recaptcha-response'));
		$userIp = $this->input->ip_address();
		$secret = get_system_settings('recaptcha_secretkey'); //key
		$data = array(
			'secret' => "$secret",
			'response' => "$recaptcha",
			'remoteip' => "$userIp"
		);

		$verify = curl_init();
		curl_setopt($verify, CURLOPT_URL, "https://www.google.com/recaptcha/api/siteverify");
		curl_setopt($verify, CURLOPT_POST, true);
		curl_setopt($verify, CURLOPT_POSTFIELDS, http_build_query($data));
		curl_setopt($verify, CURLOPT_SSL_VERIFYPEER, false);
		curl_setopt($verify, CURLOPT_RETURNTRANSFER, true);
		$response = curl_exec($verify);
		$status = json_decode($response, true);

		if (empty($status['success'])) {
			return FALSE;
		} else {
			return TRUE;
		}
	}