Coder Perfect

Javascript RegEx to allow just alphanumeric characters


I’m looking for a regex that only accepts alphanumeric characters. So far, everything I’ve tried works only if the string is alphanumeric, that is, it contains both a letter and a number. I just want one that allows me to choose between the two options rather than requiring me to use both.

Asked by User

Solution #1


^         Start of string
[a-z0-9]  a or b or c or ... z or 0 or 1 or ... 9
+         one or more times (change to * to allow empty string)
$         end of string    
/i        case-insensitive

new information (supporting universal characters)

You may obtain a list of Unicode characters here if you require this regexp to support universal characters.

/([a-zA-Z0-9u0600-u06FFu0660-u0669u06F0-u06F9 _.-]+)/([a-zA-Z0-9u0600-u06FFu0660-u0669u06F0-u06F9 _.-]+)/([a-zA-Z0-9u0600-u06FFu0660-u0669u06F $/

Persian will be supported by this.

Answered by Greg

Solution #2

This would work if you wanted to return a replacement result:

var a = 'Test123*** TEST';
var b = a.replace(/[^a-z0-9]/gi,'');

This would return:


The gi is required since it means global (not just on the first match) and case-insensitive, which is why I used a-z rather than a-zA-Z. And the “anything not in these brackets” inside the brackets means “anything not in these brackets.”

WARNING: Alphanumeric is fantastic if that’s all you need. However, if you’re utilizing this in an international market to represent something like a person’s name or a location, you’ll need to care for unicode characters, which this won’t do. For example, if your name is “lvarö,” it will be spelled “lvar.”

Answered by Volomike

Solution #3

Make use of the term “character class.” A [a-zA-Z0-9_]+$ is identical to the following:



If you don’t want to match the underscore, use /[w]| /g.

Answered by Chase Seibert

Solution #4

/^([a-zA-Z0-9 _-]+)$/

The preceding regex permits spaces within a string but excludes special characters. Only a-z, A-Z, 0-9, Space, Underscore, and dashes are permitted.

Answered by Gayan Dissanayake

Solution #5


or, if you want a minimum of one character:


A set of characters is indicated by square brackets. is the start of the input. $ denotes the end of the input (or newline, depending on your options). The letter s stands for whitespace.

There is no need for the whitespace before and after.

The parenthesis serve as a grouping operator, allowing you to extract the data you require.

EDIT: my incorrect use of the w character set has been removed.

Answered by cletus

Post is based on