Anyone who has a form on their website has seen their fair share of spam. Spam is a huge problem for site owners. It can cost businesses time and money. To fight spam, many sites put captchas on their forms. These captchas can stop spambots from spamming. But they can also stop users from filling out your form. That’s the last thing you want when you’re running a business.

Captchas force users to type random words that don’t make sense. Not only that, but the letters are so warped and distorted they’re hard for anyone to read. Users often have to try captchas many times to get it right. That’s why most users avoid filling out the form when they see one.

It’s good that captchas stop spam, but it shouldn’t come at the cost of losing users. The perfect captcha is one that not only stops spambots, but does it without hurting your form conversion rate.

Checkbox Captcha

The checkbox catpcha can stop some spambots, but not all. What’s good about this one is that it’s smaller and less intrusive than traditional captchas. All it takes is putting a checkbox generated with client-side Javascript on your form. All the user has to do is tick it–no typing necessary.

Most spambots won’t be able to tick the checkbox because they don’t parse client-side javascript shown to users. But some spambots that can detect client-side javascript through training. Although it’s less intimidating to users, it’s not 100% effective in stopping spambots.

Honeypot Captcha

Another captcha that’s less intrusive than traditional captchas are honeypots. They can stop some spambots, but not all. They may also create accessibility issues for some users.

Honeypot captchas work by hiding a text field from users through CSS. It’ll only accept entries that leave the field blank. Users can’t fill out this field because they can’t see it. But spambots will see and fill it in. The form will then reject the spambot’s entry.

Some spambots have learned to avoid honeypot text fields if they’re labeled in a way that tells users to avoid it. This presents accessibility issues for screen reader users who have CSS disabled. If the label on the honeypot field doesn’t tell them not fill out the honeypot, they won’t know to avoid it.

You could give the honeypot field a common label, such as “name”, to trick the spambot into filling it in. But it would also trick screen reader users to fill it in too. Honeypot captchas are not 100% effective at stopping spambots, nor are they accessible to all users. But they are far better than traditional captchas.

Slider Captcha

The slider captcha separates itself from the rest of the pack. It stops 99% of spambots because most can’t interact with the slider. It’s also user-friendly because all users need to do is slide the knob across to verify they’re not a spambot. And all mobile users need to do is swipe.

One potential drawback is that keyboard-only users might not be able to activate the slider if you don’t make it accessible. If you use this captcha, you have to make it keyboard accessible. Follow these accessibility guidelines so that all users will be able to activate your slider.

Final Thoughts

Traditional captchas are the worst. Stopping spam should not come at the cost of stopping users from filling out your form. In the battle of captchas versus spambots, the slider captcha is the most effective. It’s not only easy for users to use, but it fights spam without hurting form conversion rates. The war on spambots is far from over. But this is the best of what’s out there for sites who don’t want to lose users.

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