Does Your Website Need Some CAPTCHA?

CAPTCHA's, often more colloquially known as "those annoying squiggly word things," are used to prevent automated submissions from being submitted. In other words, they are used to make sure that nobody can post spammy comments or fill out forms with spam data.

Though CAPTCHA's have been around for a while now, the technology has come a long way since it was originally invented. To start things off, there are two main types of CAPTCHA; text and image-based. There are also more sophisticated CAPTCHA's, such as those that have multiple levels of CAPTCHA's, ones that utilize voice recordings with audio-recognition software.

But for the purpose of this article, I'll be focusing on text-based CAPTCHA's. There are two main types of text-based CAPTCHA's; the more common of the two is a standard box, or an image and its caption. The other type is a text box with an image of a text caption ("textbox"). Though there are many different ways to design a CAPTCHA, they all work in order to test whether or not someones program can read/understand the words.

When it comes to text-based CAPTCHA's, the main benefit is that the user can read them, which gives them an advantage over other forms of CAPTCHA's where the user either can't or aren't allowed to see/read them. When it comes to web applications, if somebody is using a very popular language (such as English), or has a good typing speed, they can circumvent most of the CAPTCHA's in place. However, even with these two problems, there are still ways you can detect that a person is attempting to cheat or hack your website.

Because of the advantages that CAPTCHA's have over other forms of anti-spam measures (such as CAPTCHA plus), you will find many websites wanting to use them. However, there are still some websites who don't want to use them at all, or who have problems with using them. Because of this, there are many different ways a site can implement a CAPTCHA. Depending on your website design needs/requirements, you can choose from one of these:

Screen Captures : Some websites allow users to upload images directly onto their website and then automatically generate captchas from those images. Though this is a simple approach, it can be both time-consuming and tedious. One of the main advantages to screen captures is that there doesn't have to be any special software or plugins necessary besides what the website already uses.

Media : This is a combination of an image CAPTCHA plus an audio CAPTCHA (such as those created using wav2c). In this case, the site will generate two CAPTCHA's from your uploaded image; one for your textbox and one for your audio file. Because it's simply a matter of making two CAPTCHAs from one file in most cases, it's unlikely that somebody will be able to cheat these CAPTCHAs.

Conclusion: Though there are several benefits that come with using CAPTCHA's on your website, there are still some drawbacks. Though it is generally easy to implement CAPTCHA's into your website, it does take time and manpower to do so. It can also be very difficult if you need to create two or more CAPTCHAs for the same type of text. And even though the user can read the text, sometimes they'll have a hard time reading the captchas. Because of this, it's important when designing your website that you know what benefits are going to cost you versus what benefits you're obtaining from these CAPTCHAs.