What's New in BotDetect CAPTCHA v3.0

Please Note

This page applies to BotDetect™ CAPTCHA component version 3.0.0, and outlines changes from 2.x versions of BotDetect CAPTCHA for previous customers.

For a complete list of changes added in the latest release, please consult the release note pages for BotDetect PHP CAPTCHA, BotDetect ASP.NET CAPTCHA, or BotDetect ASP CAPTCHA.

The BotDetect v3.0 Captcha control release includes numerous changes from BotDetect v2.0 releases. This page contains a brief overview of the major improvements.

While reading, you can also see many of the mentioned improvements in action by running the BotDetect Features Demo and BotDetect Image Styles Demo.

Table of Contents

CAPTCHA Internationalization

BotDetect 3 now supports international CAPTCHA generation, allowing easy Captcha localization using standard locale strings ("en-GB", "ru", "zh-Hans"). The Locale setting affects both the character set used for Captcha code generation and the language used for sound Captcha pronunciation.

BotDetect CAPTCHA v3 Localized Pronunciation Examples

Multi-language Pronunciation Sound Packages

To allow maximum flexibility in choosing the locale support that suits your needs, sound resources have been separated from the main component into external language-dependent sound packages. These can be downloaded separately from the BotDetect localizations page when you need them.

Latin Charset CAPTCHA

BotDetect CAPTCHA Latin CAPTCHA Image screenshot

Greek Charset CAPTCHA

BotDetect CAPTCHA Greek CAPTCHA Image screenshot

Hebrew Charset CAPTCHA

BotDetect CAPTCHA Hebrew CAPTCHA Image screenshot

Hangul Charset CAPTCHA

BotDetect CAPTCHA Hangul CAPTCHA Image screenshot

Han Traditional Charset CAPTCHA

BotDetect CAPTCHA Han Traditional CAPTCHA Image screenshot

Katakana Charset CAPTCHA

BotDetect CAPTCHA Katakana CAPTCHA Image screenshot

Cyrillic Charset CAPTCHA

BotDetect CAPTCHA Cyrillic CAPTCHA Image screenshot

Arabic Charset CAPTCHA

BotDetect CAPTCHA Arabic CAPTCHA Image screenshot

Devanagari Charset CAPTCHA

BotDetect CAPTCHA Devanagari CAPTCHA Image screenshot

Han Simplified Charset CAPTCHA

BotDetect CAPTCHA Han Simplified CAPTCHA Image screenshot

Bopomofo Charset CAPTCHA

BotDetect CAPTCHA Bopomofo CAPTCHA Image screenshot

Hiragana Charset CAPTCHA

BotDetect CAPTCHA Hiragana CAPTCHA Image screenshot

CAPTCHA Security

All aspects of BotDetect Captcha functionality are more secure in BotDetect v3 than they were in any previous version.

CAPTCHA Code Security Improvements

Captcha codes can now be set to expire after a user-defined timeout period (independent from Session timeouts or any other external factors). This helps prevent attacks which reuse the Captcha on other sites (controlled by the attacker).

CAPTCHA Image Security Improvements

BotDetect CAPTCHA Component v3 Security

Captcha images generated are much more randomized, often using random fonts, colors, effects and positioning separately for each character in the image (instead of text as a whole like BotDetect v2 used to work).

Combined with an increase in segmentation challenges (character overlap etc.), this makes the Captcha images more resistant to any automated solving attempts.

BotDetect CAPTCHA v3 Sound Styles

CAPTCHA Sound Security Improvements

Captcha sounds now use 10 new sound styles instead of the BotDetect v2 clear audio, each style using a unique combination of randomized silences, effects and noises. This makes the Captcha sounds much more resistant to any automated audio analysis, especially since the sound style used for each individual Captcha can be randomized in signature BotDetect fashion.

CAPTCHA Usability

All security improvements mentioned in the previous section have been paralleled by equivalent usability improvements that make BotDetect v3 the most usable Captcha release up to date.

CAPTCHA Code Input Usability Improvements

For example, while the Captcha code timeout might be significantly shorter if you decide so, it will by default also be paired with automatic reloading of Captcha images containing expired codes. This ensures the security improvement doesn't come at a high price - hindering the user experience.

Further client-side improvements include automatic user input clearing on reloads, auto-focusing the input field on reload and sound icon clicks, and optional user input auto-lowercasing now being built-in instead of requiring custom JavaScript code.

BotDetect CAPTCHA Component v3 Usability

CAPTCHA Image Usability Improvements

All Captcha image styles have also been revised for human readability, resulting in: the Captcha characters taking up a larger percentage of the image surface, distortions and noises interfering with legibility being toned down, and the resulting images looking aesthetically better than ever.

BotDetect CAPTCHA Component v3 Usability

CAPTCHA Sound Usability Improvements

BotDetect v3 Captcha sounds will now be played using the new HTML5 <audio> element in browsers that support it, expanding the number of users who will be able to play sound Captchas without installing media player plug-ins.

CAPTCHA Customization

BotDetect v3 is also the most configurable BotDetect release ever, exposing configuration properties and settings allowing customization of many and diverse Captcha aspects.

BotDetect CAPTCHA Component v3 Customization

You are now able to customize the character set used for Captcha code generation, filter the resulting codes for inappropriate sequences, fit the Captcha image color scheme to your website design, easily change the reload and sound icons and their titles...

These many options allow you to tailor the Captcha appearance and behavior to fit your requirements, and - paired with the new localization options - to the unique needs of your target audience.

Packaging & Licensing

BotDetect CAPTCHA Component v3 Packaging

BotDetect v3 setup packages have been refined, making them both easier to use and more compatible with newer Windows, IIS and .NET versions.

To make BotDetect distribution and deployment convenient on machines where running the setup package is not an option, a new binary distribution has been introduced. A simple .zip archive is available for download, containing the same files as the setup packages would install.

Samples & Demos

Web applications coming with the BotDetect installation have also been reworked. They are reorganized into Demos, Integration Samples and Captcha Options Samples, each coming with instructions and explanations on the forms themselves. They are also easier to access and navigate from the new Web Application Index page.

Beside technical improvements in Application Pool and Virtual Directory organization, deploying the web applications to the local IIS instance is also no longer done manually, but automatically by selecting the option during setup.


A new BotDetect CAPTCHA Free Component replaces the old Trial version, and functions indefinitely with certain limitations.

A new Hosting Edition license level provides an appropriate license level for server hosting companies, who were not properly covered by previous license levels.

Please Note

This page applies to BotDetect™ CAPTCHA component version 3.0.0, and outlines changes from 2.x versions of BotDetect CAPTCHA for previous customers.

For a complete list of changes added in the latest release, please consult the release note pages for BotDetect ASP.NET CAPTCHA or BotDetect ASP CAPTCHA.