What is a CAPTCHA Test?
CAPTCHA (or Completely Automated Public Turing for Telling Computers and Humans Apart!) is the acronym given to a series of tests that have been developed to tell whether a website visitor is a Computer or a Real Person.
You will probably have noticed these tests on many different websites that you visit, most notably where you are submitting your details to the website owner for registration purposes, or where you are gaining access to a restricted part of a website (your online banking account details, for instance). Using a CAPTCHA technique will reduce SPAM on your website.
The most common form of CAPTCHA test appears as distorted text within an image. You need to enter the text string represented by the characters in the image before you pass the test. Computer programs cannot (generally) pass these tests as the text is typically part of a jpeg image that it cannot decipher.
Why might I need a CAPTCHA test on my Website?
If you can answer ‘yes’ to any of the following, then CAPTCHA may be an important addition to your Website…
- Do you use forms on your website to capture visitor details which are then emailed to you (or someone else)? You need to prevent spam attacks on your Website – this is more common than most people realise, and it may well be happening without your knowledge! If you use forms to capture visitor information, which you then send as an email to someone in your organisation, then you could unwittingly be providing the vehicle for unscrupulous spammers to email their details all over the www, using your Domain (and bandwidth) to do it!
- Do you allow visitors to sign-up for a product or service by entering their details on your website?
- Do you provide a Directory Listing service that allows individuals or organisations to list their details on your Website? Is your Directory getting large numbers of inappropriate entries?
- Is your Blog being devalued by the addition of messages that contain links to completely unrelated websites?
…and the downsides?
A few visitors may be discouraged from sending you an enquiry because of the extra ‘obstacle’ that you have put in their way. Also, some visually-impaired visitors may find it difficult to read the CAPTCHA text, and for this reason, you may want to provide an ‘alternative’ test to validate them.
The decision as to whether you incorporate a CAPTCHA test into your website will ultimately be influenced by a number of factors. There are the costs of implementing it, and the potential to alienate some visitors on the one hand. On the other hand, it may encourage other visitors to use your site because you appear serious about security issues. It will certainly reduce the likelihood of successful spamming attacks on your site!