JavaScript Email Regex with Example Codes

In this article, you will have to learn the JavaScript email regex validation using regular expressions, providing you with the examples and codes to implement on your projects.

Whether you are creating a website, a web application, or an online form, assuring accurate and valid user input is necessary.

One of the most simple inputs is email addresses, and validating them correctly can greatly improve user experience and data integrity.

The Importance of Accurate Email Validation

In the digital age, email addresses serve as a primary means of communication. When users input their email addresses on your website, it is important to assure that the provided addresses are valid.

To prevent issues such as bounced emails or failed communication attempts. This is where JavaScript email validation comes into performance.

Example of Using JavaScript Email Regex

To perform email validation adequately, you can use regular expressions, typically referred to as regex.

Regular expressions are powerful tools for pattern matching and allow you to determine specific patterns that an input string must compatible.

For email validation, we’ll create a regex pattern that follows the standard format of email addresses.

Here’s an example code of a JavaScript function that uses regex for email validation:

function validateEmailSample(email) {
    const emailRegexValue = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
    return emailRegexValue.test(email);

In this example, the validateEmailSample function takes an email address as an argument and tests it against the defined regex pattern.

The pattern assures that the email address starts with alphanumeric characters, followed by the “@” symbol, then another sequence of alphanumeric characters, a period, and finally, a top-level domain (TLD) with a length of 2 to 4 characters.

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JavaScript Email Regex Explanation

Let’s break down the components of the email regex pattern:

  • ^[a-zA-Z0-9._-]+:
    • This part matches the username portion of the email, allowing alphanumeric characters, dots, underscores, and hyphens.
  • @:
    • This matches the “@” symbol, which separates the username from the domain.
  • [a-zA-Z0-9.-]+:
    • This matches the domain name, allowing alphanumeric characters, dots, and hyphens.
  • \.:
    • This escapes the dot, assuring it’s treated as a literal character.
  • [a-zA-Z]{2,4}$:
    • This matches the top-level domain (TLD), allowing 2 to 4 alphabetical characters.

Implementing Email Validation on Web Forms

Now that we have our email validation function, let’s move on into how to implement it on a web form using JavaScript.

Suppose you have an HTML form with an input field for the email address.

Let’s see an example code:

<form id="emailForm">
    <label for="email">Email:</label>
    <input type="email" id="email" name="email">
    <button type="submit">Submit</button>

You can improve the form by adding JavaScript to validate the email address before submission:

document.getElementById("emailForm").addEventListener("submit", function(event) {
    const emailInputValue = document.getElementById("email").value;
    if (!validateEmail(emailInputValue)) {
        alert("Please enter a valid email address.");

In this example code, we’re connecting an event listener to the form’s submit event.

When the form is submitted, the listener checks if the entered email is valid using our validateEmail function.

If the email is not valid, an alert is displayed, and the form submission is prevented.

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How does regular expression simplify email validation?

Regular expressions provide a clear and flexible way to define complex patterns. In email validation, a single regex pattern can capture different email formats, making validation efficient.

Can I use a library for email validation instead of regex?

Yes, there are libraries like “email-validator” in JavaScript that provided pre-built functions for email validation. However, understanding regex-based validation can be valuable for custom requirements.


In conclusion, by implementing proper email validation using JavaScript and regex, you can assure that user data remains accurate and communication channels stay open.

The provided examples and codes give you a solid foundation to integrate effective email validation into your projects.

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