How to Reduce Spam Form Submissions Without CAPTCHA—and Why it Matters

Dealing with spam form submissions is time consuming and irritating—for everyone. We investigated different CAPTCHA strategies to understand how each influences conversion rates and determined the best approach.

Chances are, you’ve been CAPTCHA’d.

Invented in 1997, CAPTCHA (short for Completely Automated Public Turing test to tell Computers and Humans Apart) requires a website visitor to type in a series of numbers or letters that are displayed as a distorted image in order to prove they are a real person.

In case you need a refresher, they look like this:




Yep, those annoying things are what we’re talking about. While annoying, they are there for a reason: to reduce spam form submissions on your site.

That seems like a good idea. After all, a recent analysis of internet usage discovered that nonhuman sources accounted for roughly 48 percent of all traffic to thousands of sites in the 1st quarter of 2016 alone.

Yikes. And, chances are pretty high that you’ve gotten a lot of fake “leads” on your website—form completions that turn out to be nothing but bot spam. So it would stand to reason that adding a CAPTCHA to your site forms would be a relatively good thing to do, right?

Not so fast.

Are CAPTCHAs really the best way to reduce spam form submissions? Does that extra step affect the likelihood of an actual person filling out your form? If so, how?

Here’s our take—backed by our own internal research.

The Benefits of CAPTCHA: Less Spam Form Submissions & Accurate Conversion Metrics

I’ll start with the good: CATPCHA does result in less spam-generated forms, meaning that your conversion metrics in Google Analytics will be much more accurate.

That is a great benefit for marketers, of course.

Many of us know how frustrating it can be to remove spam form completions and recalculate conversion metrics. With CAPTCHAs, less time is required to separate spam from actual leads. Fewer spam forms submitted also means more accurate conversion numbers.

The Dark Side of CAPTCHA: Lower Conversion Rates

That all seems good, right? Well…not so fast. It turns out, adding CAPTCHA to a site form could reduce the amount of forms you’ll receive from actual people:

  • A study done by Moz found that although spam was reduced by 88% with CAPTCHAs turned on, there were still 159 lost conversions. This could be attributed to how challenging users find answering the CAPTCHAs correctly on the first try.
  • In a study by Webnographer, 62% of participants got the CAPTCHA correct on the first attempt, and 15% failed to pass the CAPTCHA completely.

Beyond benchmark studies, we’ve tested this theory and found it to be true for a portion of our clients as well. The addition of CAPTCHAs may help you weed out bots, but it may also keep people from converting on your site.

That’s not ideal. 

Honeypot: The (better) Alternative to CAPTCHA

So, what’s the solution? Is there a way to reduce spam form submissions without adding an extra step to your forms that keeps people from filling them out?


We’ve landed on a technical solution known as Honeypot.

Invisible to site visitors, a Honeypot is a hidden CSS element that is visible only to bots. When a bot lands on a form page, they will “see” an additional field that a human does not see. If GA tracking is implemented correctly and the bot fills in the honeypot field, the form submission will not be tracked as a conversion.

That gives marketers a true view of conversion metrics on their site and removes the need for a manual sort & delete process, all without adding an additional step to their form fields.

It’s a win win.