Captcha forms, having to type in obscure numbers and letters into a form to verify you’re a human is almost as annoying as receiving spam its self. I’ve spent some time thinking about an alternative to a captcha form that still detects if the form submission is spam without the need for users to enter an annoying code, here is the solution I’d like to share with you.
The theory is as follows; when a spam bot comes to your website, it does not see your website as regular users, nicely styled with CSS… it sees code, specifically forms, textareas and text inputs, then it fills them out and submits the form.
How do you stop this without a captcha form?
Create a text input field & hide it with CSS.
Create a textbox that the bot will presume is just a field it can exploit with rubbish and label it with an indicator to let any viewers without the privileges of CSS know that it is to be left blank.
Disregard submissions with a value for this field.
The above example is in PHP, it basically aborts the script if there is a value entered for the field!
I’ve been running this on my website and websites I’ve built for the last year or so and it has cut out all spam, give it a try let me know how you get on!