From the blog

Gotta CAPTCHA them all

  • Technical
  • User Experience

13 Apr 2016

If I asked you fill out a form to read this article, would you do it? Most people wouldn’t. Filling out forms is not exactly one of the simple joys of life and when it comes to online forms there is more to consider than just whether or not your pencil will break.

Online forms are one of the main areas where your site can be compromised by computer programs designed to spam your blog or create fraudulent user accounts. One of the most widely used ways to prevent these programs from filling out a form is to use a CAPTCHA program.

CAPTCHA: Completely Automated Public Turing Test to Tell Computers and Humans Apart

A CAPTCHA is a program that can create tests that humans can easily pass but plays tricks with computer programs. We’ve all seen the old CAPTCHAs that relied on visually muddled images of words or audio prompts to test if you are a person or a program.

Those used to be bulletproof, but we’ve learnt never to underestimate computers. Today’s Artificial Intelligence can solve these problems with 99.8% accuracy. Of course, CAPTCHA has come forward since then with Google’s reCAPTCHA program using sophisticated risk analysis to determine if a user is a human or a robot.

Of course regardless of how effective they are, great minds differ on the benefits of using CAPTCHA codes on your site. We’ve outline some of the pros and cons of using these amazing yet frustrating programs.



Contribute to human knowledge

CAPTCHA programs like Google’s reCAPTCHA project take the time that you spend filling in forms and turn it into digitizing books, improving maps and solving difficult AI problems. Who knew that we could use boredom to improve the world?

Accessible options

Many CAPTCHA programs are accessible for the visually impaired, with audio options available. In a world where design sometime ignores accessibility, having security for all people is vitally important.

Too hard for computers

Current computer programs can do many things easily, like complex mathematics or pantsing world Go champion Lee Sedol. But they struggle with things that most people take for granted such as using vision or hearing.


Too hard for humans

Solving a CAPTCHA can be difficult. We’ve all failed a few in our time. CAPTCHA programs slow down form completion time which could affect conversion rate on your site. Good form design means making things easier, which doesn’t always sit well with security.

You’re passing the work onto the user

CAPTCHAs are designed to prevent spam and hacking. That’s a problem on your side, not the user side. Users will leave sites if they can go somewhere else where they have to do less work.

Designed to be broken

CAPTCHA codes are designed to be broken. We’ve already explained how Google found old-style CAPTCHAs to be not secure. Cryptographers gain immense value from designing programs that can solve CAPTCHA codes, but that doesn’t help you much when your site is filled with spam.


That’s just a few of the arguments for and against CAPTCHA codes. Fortunately there are many alternatives available to these little programs such as server-side validation, ASKIMET anti-spam and honey pot fields.

To find out more about alternatives to CAPTCHA programs, contact us online or call our office on 08 9200 4429.