Some of these creative and unique CAPTCHA’s can be downloaded or purchased so they can be used in your own projects. You could also use the very popular reCAPTCHA.
A great and intuitive idea for a captcha, designed and developed by Joss Crowcroft. In order to submit the form, you’ll need to copy the shape in the box, as indicated. If the shape is too hard to draw you can ask for a new one. The newest version even adds mobile support!
Another great way to validate if your visitor is human. It’s like a submit button only with a safety check. The script shows you the icon you have to click. All you have to do is pick the right icon and you’re in. You can buy this script from CodeCanyon for only $4.
This is probably my favorite captcha because it’s simple and easy to use. Slide the cursor to the end of the line to validate yourself. Similar to DISTCHA.
Fun Captcha makes it fun to complete a Captcha form while maintaining the core functionality. Fun Captcha is designed as a game of Tic Tac Toe. The user is presented with an almost complete game and is asked to get 3 X’s in a row.
Ajax Fancy Captcha is a jQuery plugin that helps you protect your web pages from bots and spammers.In order to do that you are asked to drag and drop specified item into a circle.
A similar captcha as the previous one. In order to pass the “are you human” test, the user has to drag the numbers from 1 to 6 into order.
This captcha is a bit more complex. It’s a WordPress plugin that will draw a random 5% or 10% resistor and four color band sliders beneath it. The commenter needs to match the colors on the sliders to the colors on the resistor.