v0.1.2

Copyright 2015 Nic Jansma

http://nicj.net

Licensed under the MIT license

adblock-detector.js attempts to detect if the advertising on your site is being blocked by software in the visitor's browser such as Adblock Plus.

As of March 2014, this library is able to detect Google AdSense ads being blocked on Windows machines when Adblock Plus or Remove It Permanently is installed for the following browsers:

• Internet Explorer 11
• Firefox 27
• Chrome 33

adblock-detector.js may work in other environments, such as other browsers, browser versions, ad publishers and ad-blockers, but it has not (yet) been thoroughly tested elsewhere. If you have experience with this library working in other environments, please update this README. Validating and updating adblock-detector.js to work in new environments will be an ongoing process.

NOTE: This library is intended to be used to monitor your ad-blocker rate, or to replace blocked ads with other non-annoying content such as a gentle text suggestion to donate to the site if the visitor feels so inclined. Replacing blocked ads with other ads will likely upset your customers.

You can see this script in action on sarna.net, which gives a gentle Please donate Bitcoins if you enjoy this site message to the visitor if ads are blocked. The visitor is also given the opportunity to hide the message for a year if they do not want to continue seeing it.

Releases are available for download from GitHub.

Development: src/adblock-detector.js - ~3.7kb

Production: dist/adblock-detector.min.js - ~500b (minified / gzipped)

adblock-detector.js is also available via bower. You can install using:

bower install adblock-detector

NOTE: adblock-detector.js requires jQuery.

Include adblock-detector.js in your HTML:

<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="adblock-detector.min.js"></script>

Once imported, a global AdblockDetector element is added to the top-level window object (if not using AMD).

Otherwise, adblock-detector.js can be used as an AMD / require.js module.

To detect if ads were blocked on the page, you can either use AdblockDetector.hasAdsBlocked(element) to detect if an individual ad container has been blocked, or use AdblockDetector.detect(...), which waits for the document.ready event and then checks all of the ads on the page to see if any have been blocked.

To help adblock-detector.js determine if ads are being blocked, all of your ads should be wrapped up in a container element, such as the following:

    <div class='ad-container'>
        <script type='text/javascript' src='http://pagead2.googlesyndication.com/pagead/show_ads.js'></script>
    </div>

This container element helps AdblockDetector find where ads should have appeared in the DOM so it can inspect them.

Two complete examples are provided in the examples/ folder:

• analytics.html - Uses Google Analytics (Universal) to monitor which users have an ad-blocker installed by setting an Google Analytics Dimension.

• please-donate.html - Gives a gentle plea to users who have an ad-blocker installed, requesting Bitcoins if they enjoy the site. Also gives an option to hide the nag message if the user doesn't want to see it anymore.

More examples:

After setting up your ad in a <div class='.ad-container'>, you could check to see if it has been blocked via the hasAdsBlocked() function. You should wait a small period after the document.ready event for ads to be asynchronously loaded before checking (for example, 500 to 2,500 ms).

    <div class='ad-container' id='ad1'>
        <script type='text/javascript' src='http://pagead2.googlesyndication.com/pagead/show_ads.js'></script>
    </div>
    <script>
        $(function() {
            setTimeout(function() {
                alert('Ads blocked? ' + AdblockDetector.hasAdsBlocked($('#ad1'));
            }, 3000);
        });
    </script>

After setting up your ads in <div class='.ad-container'>, you can check to see if any ads have been blocked via the detect() function:

    <div class='ad-container' id='ad1'>
        <script type='text/javascript' src='http://pagead2.googlesyndication.com/pagead/show_ads.js'></script>
    </div>
    <script>
        AdblockDetector.detect({
            timeout: 3000,
            selector: '.ad-container',
            blocked: function(element) {
                alert(element + ' had its ads blocked');
            },
            complete: function(adCount, adsBlockedCount) {
                alert(adsBlockedCount + ' ads blocked out of ' + adCount);
            }
        });
    </script>

After detecting that your ads have been blocked via the detect() function, you can replace the ad content with something else. For example, you could inject a gentle Please Donate text suggestion instead.

    <div class='ad-container' id='ad1'>
        <script type='text/javascript' src='http://pagead2.googlesyndication.com/pagead/show_ads.js'></script>
    </div>
    <script>
        AdblockDetector.detect({
            timeout: 3000,
            selector: '.ad-container',
            blocked: function(element) {
                $(element).html('Please donate Bitcoins to us at <a href="bitcoin:1PVhFgNmTNmHsCEdNA2HHH18pFNiaVLUa9">' +
                    '1PVhFgNmTNmHsCEdNA2HHH18pFNiaVLUa9</a> if you enjoy this site.');
            }
        });
    </script>

Determines if ads are being blocked in the target element (ad container).

• element HTMLElement ad container to check (HTMLElement)

boolean True if the matching ad container had its ad blocked

Waits for document.ready, then looks for ads matching a selector to see if any ads were blocked.

• opts Options (object)

  • opts.timeout Timeout before document is checked (number, default: 3000)

  • opts.selector jQuery selector of ad containers (string, default: '.ad-container')

  • opts.blocked Function that fires when a container's ads have been blocked (function(element), default: null)

  • opts.complete Function that fires after all ads have been checked for being blocked (function(adCount, adsBlockedCount), default: null)

    • adCount is the number of ads that matched the selector
    • adsBlockedCount is the number of ads that were blocked

adblock-detector.js tests are found in the test/ directory, and must be run in your web browser:

test/test.html

To run the test, you need a valid Google AdSense publisher account. Once you have an account that can serve ads, change the constant in test.html that specifies which AdSense account to use:

//
// NOTE: Modify this with a valid client ID to test
//
var PUB_CLIENT = "pub-123xyz";

The tests are run manually. You should load the test.html in your browser of choice and select either the Run Tests w/ NO Ad Blocker or Run Tests w/ Ad Blocker buttons depending on your situation.

• v0.0.1 - 2014-03-22: Initial version
• v0.1.1 - 2014-04-08: Detects Remove It Permanently (Firefox addon)
• v0.1.2 - 2015-03-12: Wraps IFRAME access in a try/catch to avoid cross-origin exceptions