PHP driven form reCAPTCHA validation tutorial (With AJAX) This is a small github repo with a step by step tutorial how to implement a Google invisible reCAPTCHA (v2) to an existing php form.

PHP form validation ensures that user input is safe and meets predefined rules. By sanitizing input and using proper validation techniques, we can prevent security vulnerabilities and improve data ...

You can use PHP's filter functions to filter/validate the form input. Here is a good tutorial to get you started. The email and URL filters aren't great (there was a recent discussion here on that ...