5 Alternatives to the CAPTCHA test

CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) tests in on-line forms are a frustration, but seemingly necessary to prevent spam and malicious activities. Often it is difficult to read the characters that are displayed, and sometimes require a number of attempts.

Is there a better way to determine if a form is being submitted by a human?

We've put together a short list of some alternative methods to determine if the user is a Bot or a real person:

1. Hidden form fields - Hidden from the human user using CSS or JavaScript, a Bot will "see" this field and fill it in. One downside is it can create a problem for screen readers.
2. Confirmation Check-boxes - Like the hidden field, a human can distinguish between "Is a human" and "Is a robot", only selecting one option. Bots aren't able to tell between the two questions and fill both check-boxes, allowing you to reject the submission.
3. Timestamps on forms - A human takes time to read the form, and fill in their information. A Bot will fill in all the fields much faster. If a form is submitted in under a certain amount of time, you can almost determine that it is from a bot.
4. Verified Sign In - Require your users to sign into your website beforehand. This allows you to remove the need for any testing as the human user has already been verified.
5. The logic test - Create a simple logic test like match the colour displayed, or complete a simple puzzle or game that a human could easily solve but a Bot can't determine. This one could also create problems for screen-readers however.