What is the regex for domain name?

The regex pattern for domain name is `^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$`. This pattern validates validates a domain name (no protocol).

How do I use this regex in JavaScript?

In JavaScript, create the regex with `const regex = /^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$/;` and test with `regex.test(yourValue)`. It returns `true` if the value matches.

How do I use this regex in Python?

In Python, use `import re; re.match(r'^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$', value)`. The raw string prefix (`r`) prevents Python from interpreting backslashes as escape characters.

Is this regex case-sensitive?

This pattern explicitly handles both uppercase and lowercase via the character classes. No additional flags needed.

Regex for Domain Name

Regex Pattern

^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$

Validates a domain name (no protocol)

Quick Answer

The regex pattern for domain name is `^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$`. Validates a domain name (no protocol). This works in JavaScript, Python, Ruby, PHP, Java, and most regex engines that support PCRE syntax.

Test Examples

Input	Result
example.com	✓ Matches
subdomain.example.co.uk	✓ Matches
my-site.io	✓ Matches
http://example.com	✗ No match
.example.com	✗ No match
example	✗ No match

Code Examples

javascript

const regex = /^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$/;
const isValid = regex.test(value);

python

import re
pattern = r'^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$'
if re.match(pattern, value):
    print("valid")

ruby

pattern = /^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$/
if value =~ pattern
  puts "valid"
end

php

if (preg_match('/^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$/', $value)) {
    echo "valid";
}

java

String pattern = "^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\\.)+[a-zA-Z]{2,}$";
boolean isValid = value.matches(pattern);

Frequently Asked Questions

Related Regex Patterns

Email Address

Validates a standard email address format

Email (RFC 5322 Compliant)

RFC 5322 compliant email validation with label length limits

URL (HTTP/HTTPS)

Validates HTTP and HTTPS URLs

URL (Any Protocol)

Matches URLs with any protocol (http, https, ftp, ws, etc.)

Email Username Part

Extracts the local/username part of an email address

Email Domain Part

Extracts the domain part of an email address