What Is a CAPTCHA Code?

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

By
Daniel Nations
Daniel Nations
Daniel Nations
Writer
  • University of Texas at Arlington
Daniel Nations has been a tech journalist since 1994. His work has appeared in Computer Currents, The Examiner, and other publications. He is a developer who has published apps in the Apple App Store, Google Play marketplace and Amazon Appstore; he also has worked as a data analyst and DB administrator.
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Updated on September 30, 2021

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 an acronym for: Completely Automated Public Turing test to tell Computers and Humans Apart.

Why Websites Use CAPTCHA

Illustration of a robot seeing a captcha test
Lifewire

The reasoning behind why websites implement CAPTCHA codes in 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 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 check box 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. 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.

While it is frustrating to continually be asked to enter 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. 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 refreshes the code to a new one.

CAPTCHA Security Protects Websites

If site or blog owners didn't use some type of protection like CAPTCHA, they would get dozens of spam registrants or comments a day and that's just for small websites and personal blogs that aren't very popular. You can only imagine what the most popular websites would get.

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.

FAQ
  • How do I solve a CAPTCHA code?

    CAPTCHA codes are specifically designed to thwart recognition by changing the size, angle, color, and density of a randomly generated set of characters and numbers and placing them on a colored or patterned background. Take your time and look carefully at each of the characters before you type in your response.

  • What is Google reCAPTCHA?

    Instead of using a traditional CAPTCHA code to verify that users are humans, Google uses its own reCAPTCHA system to distinguish human users from automated spammers by examining IP addresses, cookies, and other evidence. If the system cannot verify the user for any reason, it presents a traditional CAPTCHA.

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