BotDetect CAPTCHA protects ASP.NET forms from automated spam submissions. Highly customizable, secure and accessible Captcha protection is available for ASP.NET WebForms and ASP.NET MVC web applications.

BotDetect is unique among Captcha solutions in offering many Captcha image and sound styles. While each of them is easily comprehensible to human users, randomly using multiple Captcha generation algorithms makes the Captcha challenge practically impossible to pass automatically. This approach to Captcha security is validated by the BotDetect track record: we have over 2500 paying customers and not one confirmed case of automated Captcha breaking by spammers.
BotDetect provides an audio Captcha alternative to keep ASP.NET web applications accessible to the blind and other people for whom reading the Captcha code could be a problem, enabling you to make WCAG and Section 508 compliant websites.

 * 60 secure & readable Captcha image styles
 * 10 secure & accessible audio Captcha sound styles
 * Localized Captcha generation, using various Unicode character sets and downloadable multi-language sound pronunciations
 * Custom Captcha image size, format, color scheme...
 * Custom Captcha code length, style, character set, timeouts, generated code filtering...
 * Many other randomization & customization options
 * Produces XHTML 1.1 Strict, Section 508 and WCAG AAA compliant markup
 * Visual Studio .NET 2013, 2012, 2010, 2008, 2005 and 2003 Designer support
 * Medium trust environment support for shared servers
 * Fully compatible with ASP.NET MVC 5, ASP.NET MVC 4, ASP.NET MVC 3, ASP.NET MVC 2, and ASP.NET MVC 1 applications
 * Fully compatible with ASP.NET WebForms applications
 * Fully compatible with ASP.NET Ajax and jQuery Ajax validation
 * Fully compatible with SharePoint Server / Foundation
 * Tested in IE, Firefox, Chrome, Safari and Opera browsers released since 2001.
 * Full support for all Android & iOS devices

There is a newer version of this package available.
See the version list below for details.
Install-Package Captcha -Version
dotnet add package Captcha --version
<PackageReference Include="Captcha" Version="" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add Captcha --version
The NuGet Team does not provide support for this client. Please contact its maintainers for support.
#r "nuget: Captcha,"
#r directive can be used in F# Interactive, C# scripting and .NET Interactive. Copy this into the interactive tool or source code of the script to reference the package.
// Install Captcha as a Cake Addin
#addin nuget:?package=Captcha&version=

// Install Captcha as a Cake Tool
#tool nuget:?package=Captcha&version=
The NuGet Team does not provide support for this client. Please contact its maintainers for support.


This package has no dependencies.

NuGet packages (1)

Showing the top 1 NuGet packages that depend on Captcha:

Package Downloads
EasyCaptcha library for Mvc

GitHub repositories

This package is not used by any popular GitHub repositories.

Version History

Version Downloads Last updated
4.4.2 127,060 7/22/2019
4.4.1 8,929 4/8/2019
4.4.0 13,142 11/6/2018
4.3.3 7,371 10/23/2018
4.3.2 33,168 5/27/2018
4.3.1 4,270 5/14/2018
4.3.0 7,801 2/15/2018
4.2.0 36,093 4/29/2017
4.1.0 44,999 7/25/2016
4.0.1 16,517 3/9/2016
3.0.18 10,992 12/9/2015
3.0.17 5,042 10/22/2015
3.0.16 108,344 6/5/2014 2,095 4/24/2014
3.0.15 1,062 4/22/2014 8,324 2/17/2014 1,346 12/11/2013 956 12/9/2013 1,308 12/7/2013
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