automatically download captcha from webpage

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Hi!
i want to create a C# app which automatically download captcha images from a website. can somebody tells me how is it possible.?

Posted 18-Feb-12 23:28pm

saifullahiit

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Comments

Ed Nutting 19-Feb-12 5:50am

Why do you want to automatically download other websites CAPTCHA images? CAPTCHA images are normally (or at least should) be randomly generated for every request meaning no two are the same (pretty much..) so you could spend eternity trying to download all the CAPTCHA images - there are theoretically infinitely many. I suggest you try searching CP or Google for CAPTCHA image generation.

Hope this helps,
Ed

saifullahiit 19-Feb-12 6:01am

what i want is to create a widows form. put browser controls on it, and a button. a webpage will be open in the windows form containing captcha images when i click on the button it save only captcha image from webpage into local drive.

Dave Kreskowiak 19-Feb-12 14:27pm

What's the point of doing this??

Aniket Yadav 19-Feb-12 6:21am

The captcha image will change for every request. So downloading and then submitting again may not work. One option is to have a web browser control, load this webpage and fill out the form fields programatically and then wait for the user to enter captcha and then submit the form.

Ileny Francis 8-Jul-21 19:18pm

What's my chaptcha code to ilenyfrancis605@gmail.com

3 solutions

Solution 1

No, there is no automatic way to do that - a Captcha image is just an image like any other. There is nothing which marks this as a "Captcha" image, rather than a "Company logo" image instead.

Posted 19-Feb-12 0:13am

OriginalGriff

Solution 3

I want to download all of chaptcha images into my app, from a website, why?! Because I write a chaptcha solver and what is the benefit if it couldn't get all the image sources automatically?!
Any idea will be welcome.

Posted 26-Oct-16 22:08pm

maryamtooty

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FrostedSyntax · Accepted Answer · 2012-02-19T00:48:00

If you know the id of the captcha element for a certain website you can get it's src attribute and download from the url.
Here is an example of a captcha img in a div tag with the id "recaptcha_image".

HTML

<div id="recaptcha_image" style="width: 300px; height: 57px; "><img style="display:block;" alt="reCAPTCHA challenge image" height="57" width="300" src="http://www.google.com/recaptcha/api/image?c=03AHJ_Vus407GuhxqGfVSZawlQp2afR8Ov0GI0zpZolxeHbjXa5dRThbO0XWzAduWq5P7JNzA99oGPLSjuWQtnKotfv4Jy0EwkXBZv9kj9531F6YEwSop56pRTh4hOsWnO7n-CxLtH_w4pKC6OpRdw3KZZOXjgts3-Dg"></img></div>

Here is an example of how to get the image with a windows forms browser:

C#

HtmlElement ele = browser.Document.GetElementById("recaptcha_image");
if (ele != null)
{
    string imageSource = ele.GetAttribute("src");
}