# reCAPTCHA: Tips and Guidelines

**Important** : Version 1.0 of the reCAPTCHA API is no longer supported, please upgrade to Version 2.0. [Learn more](https://developers.google.com/recaptcha/docs/faq)

## User Mistakes

Making mistakes when filling out a form can be a very frustrating exprience for the user. When a user enters
the CAPTCHA incorrectly (or any other field in the form), we strongly encourage you to help them by:

- Re-displaying the form in question with the form data they entered pre-filled, so they don't have to re-enter everything.
- Adding the `error=` parameter to http://www.google.com/recaptcha/api/challenge so that the error type is displayed to the user.

## reCAPTCHA on an https site

In order to avoid getting browser warnings when you use reCAPTCHA
on an SSL site, you should replace http://www.google.com/recaptcha/api with https://www.google.com/recaptcha/api when you
request a challenge. Your request to reCAPTCHA would look like this:

```
<script type="text/javascript"
   src="https://www.google.com/recaptcha/api/challenge?k=your_public_key">
</script>

<noscript>
   <iframe src="https://www.google.com/recaptcha/api/noscript?k=your_public_key"
       height="300" width="500" frameborder="0"></iframe><br>
   <textarea name="recaptcha_challenge_field" rows="3" cols="40">
   </textarea>
   <input type="hidden" name="recaptcha_response_field"
       value="manual_challenge">
</noscript>
```

## Empty reCAPTCHA Fields


If the value of "recaptcha_challenge_field" or "recaptcha_response_field" is
not set when you are processing the form, avoid sending a request to www.google.com/recaptcha/api/verify. This allows
you to more quickly deal with simple attempts at spamming.