Jason Hendriks

nicholaswilson

<p>Hiding email addresses from spammers has a long history. There are some obvious golden goals, like making the process seamless to your visitors, and be practicable to implement. The one that often gets left out is accessibility, but in some areas this is actually a legal requirement.[1]</p>
<h4>The method</h4>
<p>To my knowledge, this plugin implements the best method so far devised. Credit goes to Roel Van Gils for this technique, which he calls Graceful Email Obfuscation.[2] The basic idea is actually very simple: use PHP and JS to hide the address effectively, and make sure the fallback can be used easily by blind or visually impaired users by using a text-based CAPTCHA.</p>
<p>The PHP code takes passed-in emails and generates simply-encoded string using alphabetic characters. It is therefore very hard to imagine what sort of spammer’s parser could possibly detect it. The only way is to load the whole DOM and jQuery to run the decryption routine. As far as we know, no bots go to those lengths, but it adds essentially no overhead if the theme or any other plugins already load jQuery; otherwise a fraction of a second might be added to page load.</p>
<h4>Comparisons with other plugins</h4>
<p>Amazingly, no other WordPress plugins seem to use this method, either offering very little spam protection, or not coping with JavaScript turned off (3-10% of users). <a href="http://www.privatedaddy.com/" rel="nofollow ugc">Private Daddy</a> comes closest, but falls at the last hurdle by offering an image CAPTCHA with no non-visual alternative. Clunky though my first code bash is, it seems to the best available at the moment if accessibility is really important to you (of course, if I did not think that, I would not have written this). There is a similar Drupal plugin.[3]</p>
<h4>Comparisons with other methods</h4>
<p>The most viable alternative methods are:</p>
<ol>
<li>Using images (<em>cf.</em> <a href="http://www.facebook.com/" title="Facebook" rel="nofollow ugc">Visagefolio</a>). This requires typing and is a pain for everyone.</li>
<li>Poor “test [at] example [dot] com” style text replacements provide no protection and annoy users.</li>
<li>Clever things like outputting “moc.elpmaxe@tset” and using CSS unicode rules to reverse it. Unfortunately these cause trouble for the blind and in some browsers make it confusing to copy and paste the link.</li>
<li>Using XML comments or CSS <code>display: none;</code> to remove elements inside the link text. There is still no clickable link, which makes it hard for the blind to use.</li>
</ol>
<h4>JavaScript fallback</h4>
<p>If there is no JavaScript, the user is taken to a page on the site using an empty content box where they are asked a simple text question to check whether they are a human. Basic sums are asked at the moment, though a wider range of questions could be added using the <a href="http://testCAPTCHA.com" rel="nofollow ugc">testCAPTCHA.com</a> service.</p>
<h4>References</h4>
<ol>
<li>See particularly ‘508’ legislation in America.</li>
<li>Original description on <a href="http://www.alistapart.com/articles/gracefulemailobfuscation" title="A List Apart: Graceful Email Obfuscation" rel="nofollow ugc">A List Apart</a>.</li>
<li><a href="http://drupal.org/project/geo_filter" rel="nofollow ugc">Drupal plugin</a></li>
</ol>
<p>Further reading:</p>
<ol>
<li><a href="http://technology.kencarlson.org/general/graceful-e-mail-obfuscation/" rel="nofollow ugc">GEO review</a> by Ken Carlson</li>
<li>Spam obfuscation comparison recommending use of this method for 508 compliance: <a href="http://doteduguru.com/id415-e-mail-obfuscation.html" rel="nofollow ugc">.eduGuru article</a> by Michael Fienen</li>
</ol>
<p><strong>Some notes and future details on <a href="http://www.nicholaswilson.me.uk/2010/04/notes-on-good-email-obfuscation/" rel="nofollow ugc">my site</a></strong></p>


Graceful Email Obfuscation

Hiding email addresses from spammers has a long history. There are some obvious golden goals, like making the process seamless to your visitors, and b …

pixeline

<p>This plugin provides an unobtrusive yet efficient protection against email harvesters / spambots. Here is a <a href="https://pixeline.be/blog/email-protector-demo-4258.html" rel="nofollow ugc">demo</a>.</p>
<p>Post/page authors may write email addresses in their article in the usual format (“john@doe.com”) without exposing them to spam email harvesters. The plugin takes care of the obfuscation, implementing a graceful degradation technique focusing on usability so as to protect your email addresses from harvesters while keeping them usable to your human visitors.</p>
<p>The plugin replaces any email address found in posts, pages, comments and excerpts, and replace them by a bit of html markup that should deceive most email harvesters: <code><span class="email">john(replace the parenthesis by @)doe.com</span></code>.<br />
If javascript is available, it will display a clickable link and display the original email to the human user. Maximum usability, maximum protection.</p>
<p><strong>Please <a href="https://wordpress.org/extend/plugins/pixelines-email-protector/" rel="ugc">rate the plugin</a> if you like it.</strong></p>
<h3>Usage</h3>
<p>Write your email addresses inside your posts and pages as usual. When the plugin is activated, it will replace them by a human-readable html string that explains how to deduce the email address, and if javascript is available (99.9% of the time), the original email address will be displayed as a clickable mailto: link. For example:<br />
    Hello john@doe.com. How are you today?<br />
will become<br />
    John( replace these parenthesis by @ )doe.com.</p>
<p>Additionally, you can specify what the mailto: link should look like by sticking a parenthesis inside of which you put the visible link text, like this:</p>
<pre><code>Hello john@doe.com(John Doe). How are you today?
</code></pre>
<p>will become<br />
    John( replace these parenthesis by @ )doe.com.</p>
<h4>inside a theme</h4>
<p>If you need to protect emails inside your Theme’s files (like the footer.php for example), you can use the function safe_email() like this:</p>
<pre><code> echo safe_email('you@domain.com'); <h3>Contribute</h3>
</code></pre>
<p>Github repo: https://github.com/pixeline/pixeline-email-protector</p>


Pixeline's Email Protector

Write email addresses without worrying about spambots and email harvesters.

Graceful Email Obfuscation vs Pixeline's Email Protector