Why Do We Need CAPTCHAs?

Ramirez's picture

I’m newbie to internet marketing. I know it’s very silly questions but I really want to know that why do we need captcha for registration to our website?

BlueStreak's picture

I've put up testing web sites with very obscure addresses that no human could find, yet the spammers are always able to find them and write very complimentary blog comments on those sites telling me how great my articles are. The article writing they compliment is complete "lorem ipsum dolor" style gibberish, and they always add a few spammer style links within their blog comments to sites for Viagra, or gold sales, or some other non-sense. And I'm sure they have scripts that write those same comments on a multitude of sites. Without protection, spammers will find and abuse any form of web communication.

One of the simple ways to thwart the spammers using automated tools is the CAPTCHA:

"CAPTCHAs, or Completely Automated Public Turing Tests to Tell Computers and Humans Apart, exist to ensure that user input has not been generated by a computer. These peculiar puzzles are commonly used on the Web to protect registration and comment forms from spam. To be honest, I have mixed feelings about CAPTCHAs. They have annoyed me on many occasions, but I’ve also implemented them as quick fixes on websites."

Source: http://www.smashingmagazine.com/2011/03/04/in-search-of-the-perfect-captcha/

riccard0's picture

It all depends on how many spambots you expect/can manage.

aluminum's picture

This isn't really a typography nor visual design question nor marketing, but...

We don't need CAPTCHAs. But we use them to be pragmatic when we don't have the technical or human resources to handle the issues associated with not using them on the back-end.

A CAPTCHA, as stated, is an attempted way to determine that the web form is being filled out by a human rather than an automated script. It does this on the client side, meaning the onus is on the customer to pass the test as opposed to handling this on the server side, which can be more effort.

General rule of thumb is to avoid them at all costs from a user experience perspective. People hate them. Only use them if there simply isn't another solution available.

AdamC's picture

The only CAPTCHA I've encountered that wasn't a pain to the user or to the designer was reCAPTCHA. All the other ones seem to punish legit users more than the spammers.

Joma's picture

CAPTCHAs reduce the effectiveness of every form they are on by significant percentages. There are alternatives, such as Akismet, and in my opinion they are worth it even if the odd spam bot still manages to get through.

I would rather manually remove occasional spam than lose 20% of my registrations or sales to have a CAPTCHA.

flooce's picture


aluminum's picture


halewilson's picture

Initially captcha was a very annoying thing but today most people are used to it.

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