Pure JavaScript/jQuery/HTML captcha

can somebody sent me a link, or to provide me an example with pure Javascript/jQuery captcha. Because I can see a lots of examples with PHP/C# ... back end. But I ne开发者_如何学Ced just Javascript .

Thanks !!

I think this is not a good idea, because if validation is made in client (js), somebody can make a script to read the correct answer.

EDIT

Anyway, if you want a useless captcha, you can play with this:

See in jsfiddle.

HTML

Pseudo-Human check.

<br/>How much is: <input type="text" id="a"/>
<br/>Answer:<input type="text" id="b"/>

<br/>
<input type="button" id="c" value="Go!"/>

JS

$(document).ready(function() {
    var n1 = Math.round(Math.random() * 10 + 1);
    var n2 = Math.round(Math.random() * 10 + 1);
    $("#a").val(n1 + " + " + n2);
    $("#c").click(function() {
        if (eval($("#a").val()) == $("#b").val()) {
            alert("Ok! You are human!");
        } else {
            alert("error");
        }
    });
});

EDIT 2:

My "captcha" hack:

// captcha hack
$(document).ready(function() {
     $("#b").val(eval($("#a").val()));
});

See in jsfiddle.

That doesn't make sense... without a backend check, the captcha is useless. bots don't use javascript anyway. All you'd be accomplishing is to annoy your users.

Check out: http://www.google.com/recaptcha/intro/

Demo here: http://www.google.com/recaptcha/api2/demo OR http://www.finalwebsites.com/demos/custom-captcha-image-script/

===========================IN SHORT====================

Add the code snippet to the page for the captcha to occur:

<script src='https://www.google.com/recaptcha/api.js'></script>
<div class="g-recaptcha" data-sitekey="YOUR_KEY_1"></div>

whenever user complete the challenge, a textArea named g-recaptcha-response with value is populated, you will collect that value and send below request to validate it: https://www.google.com/recaptcha/api/siteverify?secret=YOUR_KEY_2&response=TOKEN&remoteip=IPADDRESS

Getting the IP using js may be troublesome: http://www.ipify.org/

I'm working on an alternative captcha right now. If you'll use only client-side part of it, you'll have what you want assuming you want something just to show in the browser. It's not exactly pure javascript, since it still uses api to get a picture, and looks cool enough :D

http://photocaptcha.cu.cc

It would involve including one script on your side, but it doesn't make much much sense if you don't validate the answers ;)

There is a tutorial on jQuery with captcha located here; http://www.tutorialcadet.com/jquery-advanced-ajax-validation-with-captcha/

Hi AlexC you can validate your google recaptcha at client side also 100% work for me to verify your google recaptcha just see below code
This code at the html body:

 <div class="g-recaptcha" id="rcaptcha" style="margin-left: 90px;" data-sitekey="my_key"></div>
 <span id="captcha" style="margin-left:100px;color:red" />

This code put at head section on call get_action(this) method form button:

function get_action(form) {

    var v = grecaptcha.getResponse();
    if(v.length == 0)
    {
        document.getElementById('captcha').innerHTML="You can't leave Captcha Code empty";
        return false;
    }
    if(v.length != 0)
    {
        document.getElementById('captcha').innerHTML="Captcha completed";
        return true; 
    }
}

I wrote a tutorial on making a simple math captcha using PHP and jQuery, so it works with or without Javascript enabled. This should be very easy to integrate into your own scripts, or you can use it as is. You can download the project, extract the zip file, and it works out of the box. I hope you find this useful.

Making a Simple Math Captcha using both jQuery and PHP http://www.sinawiwebdesign.com/blog/topics/programming/jquery-and-php-and-catcha-tutorial/

Do you want to add CAPTCHA just because it sounds geeky? Don't use it unless it is really needed.