Best way to obfuscate an e-mail address on a website?

Question

Hello all. I've spent the past few days working on updating my personal website. The URL of my personal website is (my first name).(my last name).com, as my last name is rather unusual, and I was lucky enough to pick up the domain name. My e-mail address is (my first name)@(my last name).com. So really, when it comes down to guessing it, it's not very hard.

Anyways, I want to integrate a mailto: link into my website, so people can contact me. And, despite my e-mail address not being very hard to guess, I'd rather not have it harvested by spam bots that just crawl websites for e-mail address patterns and add them to their database.

What is the best way for me to obfuscate my e-mail address, preferably in link form? The methods I know of are:

<a href="mailto:[email protected]">e-mail me</a>

It works, but it also means that as soon as my website hits Google, I'll be wading through spam as spam bots easily pick out my e-mail address.

<img src="images/e-mail.png" />

This is less desirable, because not only will visitors be unable to click on it to send me an e-mail, but smarter spam bots will probably be able to detect the characters that the image contains.

I know that there is probably no perfect solution, but I was just wondering what everyone thought was best. I'm definitely willing to use JavaScript if necessary, as my website already makes use of tons of it.

Thanks in advance!

Answer 1

Don't use any obfuscation techniques here because it's probably the first place the email harvesters will look to find out how people are obfuscating emails. If you have to have your email address visible on the site don't just copy verbatim someone else's method; obfuscate it in some unique way that no other site has used so that your method won't be known to harvesters before they visit your site.

Answer 2

I use JavaScript obfuscation, take a look at this one for example:

http://www.jottings.com/obfuscator/

Answer 3

The current accepted solution is to create a contact form that allows users to email you. If you receive a lot of spam from that (I don't on my site), then you can add a captcha for good measure, and you'll be far from the "low hanging fruit" at that point.

The fact of the matter is that if you are providing a link that a user can click on to pop open their email client with your address in the To: field, then the computer is able to decipher the email address from the page and so can a spam bot.

Answer 4

I encode the characters as HTML entities (something like this). It doesn't require JS to be enabled and seems to have stopped most of the spam. I suppose a smart bot might still harvest it, but I haven't had any problems.

Answer 5

Personally, I've given up on hiding my email address. I find it easier to look into better spam-filtering solutions than worry about obfuscating. You could spend days trying to find the best way to obfuscate your address, and then all it takes is one person to sell your address to a spammer and all that work was useless.

Answer 6

Honestly, your problem may be moot if you asked the question of whether or not a mailto is really what you want to use. A lot of people who use web mail, for example, or do not have the proper mail client setup in their browser are not going to benefit from a mailto. You are exposing your email address for a function that isn't going to work for a large portion of your users.

What you could do instead is use a form to send the e-mail behind the scenes so that the e-mail address is hidden and you don't have to worry about the poor saps who won't benefit from a mailto.

Answer 7

You could do as Google do on Google Code (and Groups). Display a par tof the email, and a clickable portion ("..."). Clicking that indicates you want to know the email, and you are asked to fill in a captcha. Afterwards the email (and others?) are visible to you.

Answer 8

Apparently using CSS to change the direction of your text works pretty well. That link has a test of a bunch of other obfuscation methods as well.

Whatever you use is inevitably going to be defeated. Your primary aim should be to avoid annoying the heck out of your users.

Answer 9

reCAPTCHA offers a simple email obfuscation service. You don't need to set up an account and can start using it immediately. You can use the service as a link or as a popup.

After the captcha is solved, your email address appears as an href/mailto, so that it can be clicked/followed by users who have configured their email clients to work with their browsers.

Answer 10

I don't how well this would work. Could you not leave your email address out and make it load using an AJAX call once the page has finished loading. Not sure if spam bots can pick up the altered HTML or if they are clever enough to listen on other HTTP traffic to try and pick email addresses or if they just scan the page as it is received the first time.

Answer 11

One website I maintain uses a somewhat simplistic JavaScript means of (hopefully) keeping spambots out.

Email links call a JS function:

function sendEmail(name, domain) {
    location.href = 'mailto:' + name + '@' + domain;
}

To make sure only users who have JS enabled can see the link, write them out with this:

function writeEmailLink(realName, name, domain) {
    document.write('<a href="javascript:sendEmail(\''
      + name + '\', \'' + domain + '\')">');
    document.write(realName);
    document.write('</a>');
}   

The use of one JS function to write out a link that calls another means that there are two layers of protection.

Answer 12

You mentioned this is for your personal website. On my personal site (for example, bobsomers.com) I just have a paragraph that says this:

The best way to get in contact with me before the new site is up is to send me an email. My email address is my first name at this website. If you can't figure it out from that hint, well, you might find email more of a challenge than figuring out my address.

People seem to be able to figure that out just fine, as I get legitimate email all the time. Sometimes the best solutions don't require writing any code. :)

Answer 13

I use a different approach, and so far has worked for me. My solution is written in PHP and JavaScript, but should to be able to ported to any other server language or plain JS. I use this regex to capture user inputted emails from my CMS

$regex = '/\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b/i';

I then run the result through this function

function stopEmailHarvesting($match) {
    $find = array('.', '@');
    $replace = array(' dot ', ' at ');
    $match = str_replace($find, $replace, $match);
    return '<span class="obfuscate-email">' . $match . '</span>';
}

This renders an email as alex at domain dot com dot au.

Now, to tidy up things, I run this jQuery function on DOM ready.

var emailLinks = {
    init: function() {
     $('.obfuscate-email').each(function() {    
         var email = $(this).text();
         email = email.replace(/ at /, '@');
         email = email.replace(/ dot /g, '.');
         $(this).replaceWith('<a href="mailto:' + email  + '" title="Email \'' + email + '\'">' + email + '</a>');        
     });
    }
}

This then renders the email as it should, and so far no spam has came through. Mind you, my sites are not terribly popular, but I think this is a decent solution. Don't forget to include a good spam filter on your email, just in case.

Answer 14

If you work with PHP, you can grab a free script that does that automatically. It's called "Private Daddy" and we use it for our own online audio streaming service. Just one line of code and it works out of the box... you can grab it here

Cheers,

Reuven

Answer 15

If you say on your site that "My e-mail address is (my first name)@(my last name).com.", and your first name and last name are pretty darn obvious, that seems to be the best spam protection you're going to get.

Answer 16

Check this out.

The 'Enkoder Form' will encrypt your Email address and convert the result to a self evaluating JavaScript, hiding it from Email-harvesting robots which crawl the web looking for exposed addresses. Your address will be displayed correctly by web-browsers, but will be virtually indecipherable to Email harvesting robots.

Answer 17

One guy tested nine different ways of presenting an email address on a page and then published results on his blog.

His three best ways were:

1. Changing the code direction with CSS
2. Using CSS display:none
3. ROT13 Encryption

Caveat -- this was posted two years ago. Spam bots might've gotten smarter.