email regex not working as expected

Question

I am using the following regex to validate emails and just noticed some problems and don't see what the issue is :

/^[a-z0-9_.-]+@[a-z0-9.-]+.[a-z]{2,6}$/i.test(value)

support@tes is invalid
support@test is valid
support@test.c is invalid
support@test.co is valid

the 2,6 is for requiring and ending tld between 2 or 6 and that does not appear to be working either. I am sure I had this working properly before.

Why use regex when you can use this => http://www.php.net/manual/en/filter.examples.validation.php — Funk Forty Niner, Dec 21 '13 at 01:04
...because I also replicate in jquery as needed for validation. — user756659, Dec 21 '13 at 01:06
Thanks and sorry for missing that. I need to replicate some regexs in jquery as I am using the jquery validation plugin for custom rules. So yes, in this case I am not using php necessarily, but I duplicate the expression in both php and jquery. — user756659, Dec 21 '13 at 01:08
Javascript can always be disabled by a user, therefore I recommend you also use a server-side solution as a backup ;-) — Funk Forty Niner, Dec 21 '13 at 01:08
A valid email address can contain many many more different characters than you're allowing! — Joel L, Dec 21 '13 at 01:15

score 3 · Accepted Answer · answered Dec 21 '13 at 01:03

3

In a regex, . is a wildcard (meaning any char). you need to escape it as \.

Keep in mind though, the regex is too restrictive. You can have non-alpha numeric chars in the address, like '

answered Dec 21 '13 at 01:03

Kevin Seifert

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ahh... never even noticed... seems to do the trick. Regarding the ' I am marking those as invalid... a-z, A-Z, 0-9, underscore, hyphen, and period. Plus this handles subdomains. – user756659 Dec 21 '13 at 01:13

score 1 · Answer 2 · answered Dec 21 '13 at 01:05

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I notice you're not escaping the .. There might be more to it than that, but that jumps out at me.

answered Dec 21 '13 at 01:05

9nonnatus

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Yes, the dot should be escaped, but failing to do so opens one to false *positives*, not false negatives. And the risk of false positives tends to be very low. This is one error people usually get away with. – Alan Moore Dec 21 '13 at 07:52

score 0 · Answer 3 · edited May 23 '17 at 11:50

0

This is a decent check for an e-mail with Regex

 \w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*

However you may want to read this. Using a regular expression to validate an email address

edited May 23 '17 at 11:50

Community

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answered Dec 21 '13 at 01:08

tremor

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score 0 · Answer 4 · edited May 23 '17 at 12:03

There are many ways to regex an email address. depending on how precise and restrictive you want it, but to re-write a working regex closest to what you have in you question. This should work:

^[\w_.-]+@[\w]+\.[\w]{2,6}$

support@tes - Invalid
support@test - Invalid
support@test.c - Invalid
support@test.co - Valid
supp34o.rt@tes.com - Valid

But also keep in mind ALL the characters allowed in a valid email address - What characters are allowed in an email address?

email regex not working as expected

4 Answers4