by Doug


Internet Marketing

The impact of CAPTCHAs on website accessibility and conversion rates

I am going to begin this blog post with a bit of background knowledge just to introduce you to the concept of the term ‘CAPTCHA’.

Have you ever been trying to fill out a registration form on a website when halfway through you’ve been asked to decipher a weird looking graphic of some squashed, distorted text and type the letters into a box (much like the image to the right)? That’s a CAPTCHA.

The word CAPTCHA is an acronym for Completely Automated Public Turing test to Tell Computers and Humans Apart.  Quite simply it’s a clever test intended to make sure it’s a human trying to fill out the web form – and not some automated piece of software. They’re designed to reduce spam and prevent hacking, yet they cause many negative side effects: have you ever got to a CAPTCHA and struggled to decipher those numbers and letters and eventually given up?

CAPTCHAs decrease conversions, lower accessibility and ultimately makes you less money.

The problem with CAPTCHAs begins because they’re actually not that difficult to get-around. Specialist automated decoding software can now read CAPTCHA’s and break them with unrivalled accuracy – typically starting at around 88% [source:].

So, what do we clever humans do?  We simply make the CAPTCHA’s harder to read.  Over time this leads to an ‘arms race’ of making CAPTCHAs ever more cryptic, with the obvious result being normal everyday humans finding them increasingly difficult and frustrating to complete. I personally have had this issue and have eventually given up – and the website lost my custom and my money.  You then start to see conversion rates in your analytics program fall, the income from your website dropping and you still get the odd spam issues when your CAPTCHA has been cracked.

CAPTCHAs and conversions

At the time of writing, when searching for “captcha conversion rate” in Google, position number one shows how one website increased their conversion rate by 10% through removing their CAPTCHA.  What’s an increase of 10% worth to your business over a 12 month period? Or to put it another way how much would it cost to bring in 10% more business to your company through extra advertising?

What are the alternatives to using a CAPTCHA?

Lets name a few alternatives to CAPTCHAs [source:] and their accessibility / conversion rate issues;

  1. Logic Puzzles – simply ask a person to solve a puzzle or a sum.  What happens if this person does not know the answer to the logic puzzle? You loose the customer.
  2. Sound Output – output a list of numbers and characters for a user to type in.  What happens if this person has no speakers? You also loose the customer.
  3. Limited Use Accounts – only give access to site resources from trusted users.  How do you identify these users?  A registration form perhaps? This would still be subject to spam, adds another step to your conversion funnel and you perhaps loose that customer too.

All of these options cause annoyance to the (potential) customer and act as just one more reason why they shouldn’t bother, or even worst take their business elsewhere.

As an internet marketing specialist, I want to convert as many users as possible.  I want to remove all barriers to converting a visitor to a lead.  Here at Webexpectations we’re currently trialling a ‘passive’ CAPTCHA alternative and we’re just as keen as you are to see the results.  Of course – we won’t post our trade secrets here!

In summary CAPTCHA’s often cause more problems than the one issue they fix. I think of it this way: 250 leads with 40 annoying spam? Or 100 leads and just 15 spam.  I would rather have the 250 leads, wouldn’t you?

If you’re currently running a high traffic website with a CAPTCHA and are keen to try out our passive alternative to see if it works better and increases conversion rates then get in contact and let us know.


Leave a comment

Your email address will not be published.

ConversionWorks is now Media.MonksVisit us at