Validate email address in Javascript?

Question

What's the best way to validate an email address in Javascript?

Though this solution may be simple, I'm sure this is one of those useful things that people will be Googling for and deserves its own entry on the site

Answer 1

Just parse it with a regex, of which google will yield thouands, such as this

Answer 2

javascript can match regex:

emailAddress.match( / some_regex /);

Here's an RFC22 regular expression for emails:

^((?>[a-zA-Z\d!#$%&'*+\-/=?^_{|}~]+\x20*|"((?=[\x01-\x7f])[^"\]|\[\x01-\x7f])"\x20)(?<))?((?!.)(?>.?[a-zA-Z\d!#$%&'+-/=?^_{|}~]+)+|"((?=[\x01-\x7f])[^"\\]|\\[\x01-\x7f])*")@(((?!-)[a-zA-Z\d\-]+(?<!-)\.)+[a-zA-Z]{2,}|\[(((?(?<!\[)\.)(25[0-5]|2[0-4]\d|[01]?\d?\d)){4}|[a-zA-Z\d\-]*[a-zA-Z\d]:((?=[\x01-\x7f])[^\\\[\]]|\\[\x01-\x7f])+)\])(?(angle)>)$

Answer 3

i usually use:

var filter=/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i ;
if (filter.test(email))
{
   //do stuff
}
else
{
   //validation error
}

Answer 4

Using Regular Expressions is probably the best way. Here's an example:

function validateEmail(email) 
{ 
 var re = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\
".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA
-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/ 
 return email.match(re) 
}

But keep in mind that one should not rely only upon JavaScript validation. JavaScript can easily be disabled. This should be validated on the server side as well.

Answer 5

Answers to the questions Test/expand my email regex or How far should one take e-mail address validation? could easily be adapted for JavaScript

Answer 6

There is a good example at http://techtamasha.com/?p=47

Answer 7

Wow, lots of complexity here, if all you want to do is just catch the most obvious syntax errors, I would do something like this:

\S+@\S+

It usually catches the most obvious errors that the user makes and assures that the form is mostly right, which is what javascript validation is all about.

Answer 8

There's something you have to understand the second you decide to use a regular expression to validate emails: It's probably not a good idea. Once you have come to terms with that, there are many implementations out there that can get you halfway there, this article sums them up nicely.

In short, however, the only way to be absolutely, positively sure that what the user entered is in fact an email is to actually send an email and see what happens. Other than that it's all just guesses.

Answer 9

Not bad, a somewhat stronger regex might be something like:

/^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;

I completely agree with Paolo that regex is not the optimum solution to this problem. But don't let perfect become the enemy of good. Regex validation is certainly better then no validation at all.

Answer 10

This was stolen from http://codesnippets.joyent.com/posts/show/1917

email = $('email');
filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
if (filter.test(email.value)) {
  // Yay! valid
  return true;
}
else
  {return false;}

Answer 11

/^([\w]+)(.[\w]+)*@([\w]+)(.[\w]{2,3}){1,2}$/;

Answer 12

It's hard to get an email validator 100% correct. The only really way to get it correct would be to send a test email to the account. That said, there are a few basic checks that can help make sure that you're getting something reasonable.

Some things to improve:

Instead of new RegExp, just try writing the regexp out like this:

if (reg.test(/@/))

Second, check to make sure that a period comes after the @ sign, and make sure that there are characters between the @s and periods.

Answer 13

Here is a very good discussion about using regular expressions to validate email addresses; "Comparing E-mail Address Validating Regular Expressions"

Here is the current top expression, that is JavaScript compatible, for reference purposes:

/^[-a-z0-9~!$%^&*_=+}{\'?]+(\.[-a-z0-9~!$%^&*_=+}{\'?]+)*@([a-z0-9_][-a-z0-9_]*(\.[-a-z0-9_]+)*\.(aero|arpa|biz|com|coop|edu|gov|info|int|mil|museum|name|net|org|pro|travel|mobi|[a-z][a-z])|([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}))(:[0-9]{1,5})?$/i

Answer 14

Apparently, that's it:

/^([\w\!\#$\%\&\'\*\+\-\/\=\?\^\`{\|\}\~]+\.)*[\w\!\#$\%\&\'\*\+\-\/\=\?\^\`{\|\}\~]+@((((([a-z0-9]{1}[a-z0-9\-]{0,62}[a-z0-9]{1})|[a-z])\.)+[a-z]{2,6})|(\d{1,3}\.){3}\d{1,3}(\:\d{1,5})?)$/i

Taken from http://fightingforalostcause.net/misc/2006/compare-email-regex.php on Oct 1 '10.

But, of course, that's ignoring internationalization.