Here’s a quick tip on how to make sure Google’s reCAPTCHA form is HTML 5 valid. Basically, the attribute
frameborder="0" is no longer is necessary in HTML 5 – here’s W3C Schools opinion. However, Google’s reCAPTCHA example code and recaptchalib.php files are not updated to correct this, as you can see here:
height="300" width="500" frameborder="0"></iframe>
Therefore, simply remove the attribute
frameborder="0" and you have successfully managed to make your HTML valid. You may want to style the iframe using CSS instead now.
What about WordPress and other content management sites?
Also, remember that any WordPress sites or any other content management scripts which have plugins provided may also keep this attribute
frameborder="0" in the code. Try looking for the ‘recaptchalib.php’ file in these plugins and search for the
frameborder="0" and remove it.
Let us know below if this has helped you out. If you need any help or advice with your website, please contact us.