Javascript

How to validate an email with Javascript

Email validation is something that comes up again and again. Email validation is not tricky, presuming you have the right Regular Expression. Unfortunately, there are many ways to do RegEx on an email, and much of what you find on Google often eliminates valid emails, or even worse, doesn't work at all.

There is a standard Regular Expression known as RFC822, which is massive. I wouldn't recommend using that. Instead, you can use RFC5322, its successor, which is much shorter and easier to use. The function below will validate any email put into it:

const validateEmail = function(email) {
    const regex = /^(([^<>()[\]\\.,;:\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 regex.test(email);
}

// Returns true
validateEmail('someMail@gmail.com');

Note: this is pretty full proof, but the best way to figure out if an email is valid is to send an email to it, and see what happens. This RegEx will ensure your emails are in the right format.

More Tips and Tricks for Javascript

• The Many Quirks of Javascript Dates
• Waiting for the DOM to be ready in Javascript
• Creating and Generating UUIDs with Javascript
• A Look at the New Array Methods coming to Javascript
• Check if an Object Contains all Keys in Array in Javascript
• Web Workers Tutorial: Learn how Javascript Web Workers Work
• Making your own Express Middleware
• How to get the current URL with Javascript
• Javascript Dates and How they Work
• Javascript Arrays - How to Remove Duplicate Elements