<html> <head> <title>reCAPTCHA demo: Simple page</title> <script src="https://www.google.com/reCAPTCHA/api.js" async defer></script> </head> <body> <form action="?" method="POST"> <div class="g-reCAPTCHA" data-sitekey="your_site_key"></div> <br/> <input type="submit" value="Submit"> </form> </body></html>