House of Captcha


1. Securimage Captcha


It is a open source free captcha script for generating the complex captcha images and codes to protect your website from SPAM bots. This scripts also provides the Audio captcha for vision impaired.  This captcha is completely PHP based and requires GD library support.



Click here for Demo
Paid/Free : Free
Licenses Type : BSD License


2. reCaptcha


Telling Humans and Computers apart, reCaptcha is best captcha available. This captcha is most widely used. This captcha is present for WordPress, MediaWiki, PHP, ASP.NET, Perl, Python, Java, and many other environments. reCAPTCHA also comes with an audio test to ensure that blind users can freely navigate your site. Any person having google account can use this captcha. It also generates multiple ideas such as ESP-PIX and SQUIGL-PIX. It is hard to break this captcha using OCR and other bots.




Click here for Demo
Paid/Free : Free
Licenses Type : NA
Download Link :  NA

3. Motion Captcha


This is a good innovative captcha.  MotionCAPTCHA is a jQuery CAPTCHA plugin, based on the HTML5 Canvas Harmony procedural drawing tool by Mr Doob and the $1 Unistroke Gesture Regonizer algorithm (and the more recent Protractor algorithm improvement), requiring users to sketch the shape they see in the canvas in order to submit a form. This project can also be used for iPad and iPhone.



Click here for Demo
Paid/Free : Free
Licenses Type : NA

4. jCaptcha


JCaptcha is completely Java based captcha and is very good captcha script. It provides a good noise and different fonts. You can find documentation related to its integration on https://jcaptcha.atlassian.net/wiki/display/general/Simple+Servlet+Integration+documentation this link.




Demo : NA
Paid/Free :  NA
Licenses Type : NA


5. AJAX FANCY CAPTCHA


Ajax Fancy Captcha is one of the good innovative idea present on the web. This Captcha uses different images that need to be dragged and dropped into the circle.  This captcha is available in PHP and uses jquery extensively. It is also available for WordPress.



Click here for Demo
Paid/Free :  NA
Licenses Type : Copyright 2009 Web Design Beach. All rights reserved.

6. 3DCaptcha



This a very good captcha to tell comuters and humans apart. This capatcha is created using PHP and creates a good set of images to be recognized by humans.



Click here for Demo : NA
Paid/Free :  Free
Licenses Type :  3DCaptcha is released under GPLv3

6. Free Captcha-Service

This is one of the captcha that is available in multiple technologies(PHP,ASP,Perl,Python etc..) and multiple languages. This captcha is very weak and has same noise and font for its images. This captcha is also available for audio format.



Click here for Demo
Paid/Free :  This free as well as paid service.
Licenses Type :  3DCaptcha is released under GPLv3

7. Visual and Audio PHP CAPTCHA Generation Class


This is a simple captcha and has following features :
Multiple random TrueType fonts
Character rotation
Optional chararacter shadow support
Optional site owner display text
Random custom background images
Font size selection
Greyscale or colour lines and characters
Character set selection
Integration of validation function for checking the user entered code with the generated code
This captcha uses Flite text to speech synthesis engine to generate sound files for audio captcha. Author of this captcha has provided a good documentation for this captcha.



Click here for Demo
Paid/Free : Free
Licenses Type : BSD License

8.  freeCap Captcha

This is another PHP captcha script. It has a good noise and its font is different and good.



Click here for Demo
Paid/Free : Free
Licenses Type : GNU GENERAL PUBLIC LICENSE


9. cool-php-captcha


Fonts used in this captcha are very cool. It is very simple and easy captcha to implement. But this captcha does not have noise.



Click here for Demo
Paid/Free : Free
Licenses Type : GNU GPL v3

10. Quick Captcha


QuickCaptcha provides CAPTCHA functionality to any website running on a PHP-enabled web host. The graphic image below is easily read by humans, but not so easily by computers. This makes it difficult for someone to implement an automated mechanism to use resources that integrate this feature.
QuickCaptcha allows you to specify string length, allowable characters, color contrast, and several kinds of geometric obfuscation elements.



Click here for Demo
Paid/Free : Free
Licenses Type : GNU GPL


11. WebSpamProtect


This is one more captcha that will protect your website from spam and bots. It is compatible with PHP, ASP, Perl and ASP.net. This is a captcha also provides audio captcha. This website provides a captcha hosting service. Also allows you to customize captcha for your website. It also provides a wordpress plug-in.



Click here for Demo
Paid/Free : Paid
Licenses Type : Paid licenses of WebSpamProtect
Download Link : NA


12.  Cryptographp



Cryptographp is a PHP script for generate captchas. Cryptographp limit the robots bombarding spams and automating the forms: spaces members subscriptions, guestbooks, forums... This script is free and does not use any database. It is compatible with PHP >= 4.3.0.
Also plugins are available for WordPress, wpMu for WordPress, Symfony andGuppy. It also provides a free fonts with it.



Click here for Demo
Free/Paid : Free
Licenses Type : Cryptographp is diffused with completed CeCILL licence
The CeCILL licence is GNU GPL compatible.

13. BasicCaptcha and ProCaptcha


Snaphost provides two captcha scripts, 1.BasicCaptcha is free to use, 2. ProCaptcha is a paid version. This captcha has limited fonts and not much use of noise and there is no audio captcha to use with it. For both the version of the captcha you need to integrate their code with your form.



Click here for Demo

Paid/Free : Paid service.

Licenses Type : NA

Download Link : NA.




14.   hOOmanTest


This captcha is different one as this is created using Mootools a javascript frame work. All the captcha I found are created using server side scripts.  All other captcha are either text or audio or both. But this captcha is  not text, but we need to drag and drop the objects to prove we are human. This requires Mootools 1.2 and hOOmanTest.js.



Click here for Demo
Paid/Free :  Free
Licenses Type : NA

15. Simple Ajax Captcha


This is simple captcha with ajax in use. It is used



Demo : NA
Paid/Free : NA
Licenses Type : NA
Download Link : http://rapidshare.com/files/148361490/Simple_AJAX_Captcha.zip

16. Are you Human


Test whether you are human or not by playing games. This is one of the innovative captcha that uses a game of picking up objects and putting them in right position. It gives you some different test from other text and audio based captcha. This captcha provides service of hosting captcha.



Click here for Demo
Paid/Free : Free
Licenses Type : NA
Download link : you will need to login to get it.


17. Solve Media



This is a very different captcha and this one will help you to earn revenue. This captcha uses advertisement to test weather user is human or bot. This is a new approach for captcha allowing all the publishers and advertisers to earn revenue. In this you have to identify the brand that is shown in the captcha.




Click here for Demo
Paid/Free : Free(you can earn revenue from it).
Licenses Type : NA
Download Link : NA.



18. Fun Captcha



Fun captcha is designed as a game of tic tac toe. In this the user has to get the X in one row to prove he is a human. This another exciting approach for the captcha.



Click here for Demo
Paid/Free : Paid
Licenses Type : Private.
Download Link : NA 



19. Qaptcha


The Qaptcha is a simple jquery plugin that needs human interaction to complete the form. It is also a good innovative captcha.



            Click here for Demo

Paid/Free : Free
Licenses Type : NA


20. NLPCaptcha


     Link:  http://nlpcaptcha.in/index.html

This is another captcha that will help the publishers to earn money from their captcha. This captcha uses the advertisement to tell that user is bot or human. This captcha allows the publishers and advertisers to earn revenue.



            Demo : NA
Paid/Free : NA
Licenses Type : NA
            Download Link : NA