JavaScript and email addresses

Matt's answer:

CUTTS: Hey, everybody, I wanted to talk about JavaScript and emails. So there’s a long tradition on the web of having the mail to sort of link and then an email address. And that’s great because it lets somebody contact you. The problem is if you just put a raw email address up on the web, people have done studies, and it turns out there are people who crawl the web, looking for email addresses, “Mail to” links and those can get scraped and then sold on CDs to spammers. And so, as a result, if you put a “Mail to” link, just a raw “Mail to” link, you might get more email spam on that email address. So what some people have done is try to obfuscate the email in various ways. You could make it an image, you could spell it out like Bob at example.com and make the “@” spelled out. There’s lots of different ways that you can do it. One way that people did it is they would try to use JavaScript. So they use JavaScript to write the first part of the mail and the second part, or break it into three or four parts. And that works relatively well because the browser will shh, you know, glom it all together when it executes the JavaScript. The problem is that Google and other search engines, probably over time, are getting better at executing JavaScript. So there was somebody who had done a search and saw their email address show up in the snippet because we had executed a bunch of JavaScript and done what the browser would do to show you that email address. Google is going continue to get smarter and smarter. So, if you want to obfuscate your email, I would us a different method than JavaScript. Worst case, you can use some JavaScript that’s blocked by robots.txt, web forms work really well because then your email address doesn’t even have to appear on the web anywhere. There’s lots of ways to obfuscate using, you know, escaping of characters and things like that. But I just wanted to give you a heads up that if you only rely on JavaScript, it’s possible for Google to execute that JavaScript and then that Java–that email address could be shown in our search results. I think we received one report where one person had noticed this, and we just wanted to let you know that as we execute JavaScript, it’s more likely that you’ll see that sort of thing happen. So, it’s probably better if you can obfuscate your email address using a web form or some other method than just JavaScript.

by Matt Cutts - Google's Head of Search Quality Team

Original video: