How To Create A Google Like Captcha Control In ASP.NET

ASP.NET Team Blog
10 November 2010

Want to get that same great look that Google’s Captcha has? Check out how easy it is to set up the ASPxCaptcha control to get that same look and feel:

ASP.NET Captcha - Google Style


Here’s 3 easy steps for the ASPxCaptcha:

  1. Set a CodeLength property to 10
  2. Set the ChallengeImage's BackgroundColor property to 'Transparent'
  3. Set the ChallengeImage's ForegroundColor property to '#43B468' (you can also dynamically change the ForegroundColor on PageLoad to get different text colors just like in Google's Captcha).

Here’s the ASPX markup:

<dx:ASPxCaptcha ID="captcha" runat="server" CodeLength="10">
    <ChallengeImage ForegroundColor="#43B468" BackgroundColor="Transparent" BorderWidth="0">

Customer Request

One of the readers of this blog, John, emailed me and asked:

Mehul, In your blog re ASPxCaptcha, you show the green Captcha characters similar to Google's version. How did you do that? Would like to try it. Thanks, John

Thanks for the question John! I’m sure this post will help others too.

Appearance and Customization

The ASPxCaptcha is made of 3 key functional sub-elements:

  1. ChallengeImage – An image displayed to the user
  2. RefreshButton – A button to change the image and generate a new code (in case it’s too difficult for the user)
  3. TextBox – To enter the code displayed in the ChallengeImage

Each functional element has a wide range of properties for customization.

CodeRush’s Helpful ColorPicker

Here’s another reason CodeRush is super helpful in ASP.NET.

The handy new Color dialog in CodeRush which pops up a dialog that let’s you choose your own color:

CodeRush Color Dialog


Part of ASPxEditors Suite

The ASPxCaptcha control is part of the ASPxEditors Suite which comes with either:


Try the Google look with your ASPxCaptcha. Then drop me a line below with your thoughts. Thanks!


Follow MehulHarry on Twitter

Want to experience a better Visual Studio?

Install CodeRush by downloading the free lite version here: CodeRush Xpress

Or better yet, try the full blown package free for 30 days – CodeRush and Refactor Pro Download!

Free DevExpress Products - Get Your Copy Today

The following free DevExpress product offers remain available. Should you have any questions about the free offers below, please submit a ticket via the DevExpress Support Center at your convenience. We'll be happy to follow-up.
No Comments

Please login or register to post comments.