Alternatives to Captcha for Spambot Prevention

By | Blog | No Comments

spambot alternative

The email subscribe form is about as annoying as it is useful, especially if you haven’t thought of a way to prevent it from being abused by spambots and automated systems programmed to sign up and input bogus data.

At Enform, we reckon double opt-in and captcha safeguards are by far the most common security features against this problem, but they’re not exactly perfect.

What Can Spambots Do?

More often than not, spambots are merely annoyances, filling up your subscribers lists with fake information—easily removable. There are, however, times when spambots can leave spamtrap email addresses on your lists, which can be a nightmare to fix.

While we’ve built Enform’s Automailer to have sufficient defences against these issues, it still pays to know a fewDIY-style remedies against spambots.

CaptchasDo More Harm than Good

Captchas, those computer-generated images with codes users have to type in, are a good way to protect your subscribe forms from spambots, but they also end up penalising innocent users who simply want to complete a form.

In email subscribe lists, this translates to fewer signups due to the inconvenience of captches; in your zeal to eliminate spambots, you end up hitting genuine signups too. Think about it, you don’t want to keep jumping through hoops when filling up a form.

Captcha Alternatives

Here are much simpler alternatives to traditional captchas.


A friendly and simple alternative is the “Checkbox Captcha”, a simple and straightforward tool placed at the end of forms before submission to confirm that the user is not a spambot. This solution makes use of client-side javascriptit, keeping it hidden and inaccessible to spambots.

The catch? Not all users have Javascript-enabled browsers.

Honeypot Captchas

A solution we favour is the Honeypot Captcha, which is visible only to spambots and hidden by CSS that requires no Javascript. Ergo, in the event that a user with a screen reader sees it, you can simply place instructions that say “leave me unchecked if you’re not human” next to it.

We would like to hear your ideas and problems with spambots, the better to help us update our spambot defences. Let us know your thoughts.