What Is a CAPTCHA Code?

Here's why you need to enter those silly codes on websites

If you've ever tried to register with a website or comment on a blog and been asked to enter some crazy characters that have been all jumbled up, you know how frustrating it can sometimes be to figure out how to tell a lower case L from a number 1 or an uppercase O from a number 0.

Those crazy letter and number codes are called CAPTCHA, and they are essentially a human response test. The word is actually an acronym for: Completely Automated Public Turing test to tell Computers and Humans Apart.

Why Websites Use CAPTCHA

Person typing on a keyboard
Getty Images

The reasoning behind why websites implement CAPTCHA codes into their registration processes is because of spam. Those crazy characters are a way to check if the person registering or trying to comment is a real live human being as opposed to a computer program attempting to spam the site. Yes, it's the same reason most of us have some form of spam blocker on our email.

Some websites use other forms of human response tests nowadays. For instance, you might be asked to click inside a checkbox to confirm that you're human. Or you might be asked to identify a certain number of objects in an image.

Spam is the modern day equivalent of junk mail. But, if the spammers were in charge, the junk mail wouldn't just be in your mailbox or tied to your doorknob. It would litter your yard, bury the car parked in your driveway, plaster every side of your house, and cover your roof.

And while it is frustrating to continually be asked to enter in tangled letters from an image, it's well worth it in the long run. Anyone who has ever set up their own website or blog will get a taste of what spam is like up close and personal just weeks after going online — even if that website or blog has next to no traffic whatsoever. Those spammers find little websites and blogs fast and target them because they often don't have much security to protect them.

If you're having trouble reading the characters in a CAPTCHA code, look for a circular arrow button beside it. Clicking this allows you to refresh the code to a new one.

CAPTCHA Security Protects Websites

If a site or blog owner didn't use some type of protection like CAPTCHA against it, they would be getting dozens of spam registrants or comments a day. And that's just for small websites and personal blog that aren't very popular. You can only imagine what the most popular websites must see.

So, next time you run up against one of those images and get a little frustrated trying to tell a Q from an O, just remember not to vent your frustration at the website. Focus it on the spammers, because they are the reason we have to squint at our screen almost every time we want to register at a new website.

Article updated by: Elise Moreau