What is the regex for port number?

The regex pattern for port number is `:([0-9]{1,5})(?:\/|$)`. This pattern validates extracts port number from a url or host string.

How do I use this regex in JavaScript?

In JavaScript, create the regex with `const regex = /:([0-9]{1,5})(?:\\/|$)/;` 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':([0-9]{1,5})(?:\/|$)', value)`. The raw string prefix (`r`) prevents Python from interpreting backslashes as escape characters.

Is this regex case-sensitive?

By default, yes. To make it case-insensitive, add the `i` flag in JavaScript (`/:([0-9]{1,5})(?:\/|$)/i`) or use `re.IGNORECASE` in Python.

Regex for Port Number

Regex Pattern

:([0-9]{1,5})(?:\/|$)

Extracts port number from a URL or host string

Quick Answer

The regex pattern for port number is `:([0-9]{1,5})(?:\/|$)`. Extracts port number from a URL or host string. This works in JavaScript, Python, Ruby, PHP, Java, and most regex engines that support PCRE syntax.

Test Examples

Input	Result
localhost:3000	✓ Matches
http://example.com:8080/path	✓ Matches
192.168.1.1:443	✓ Matches
example.com	✗ No match
http://example.com	✗ No match
localhost	✗ No match

Code Examples

javascript

const regex = /:([0-9]{1,5})(?:\\/|$)/;
const isValid = regex.test(value);

python

import re
pattern = r':([0-9]{1,5})(?:\/|$)'
if re.match(pattern, value):
    print("valid")

ruby

pattern = /:([0-9]{1,5})(?:\/|$)/
if value =~ pattern
  puts "valid"
end

php

if (preg_match('/:([0-9]{1,5})(?:\\/|$)/', $value)) {
    echo "valid";
}

java

String pattern = ":([0-9]{1,5})(?:\\/|$)";
boolean isValid = value.matches(pattern);

Frequently Asked Questions

Related Regex Patterns

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Extracts the subdomain from a URL or domain name

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Detects and captures the protocol from a URL

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Extracts key-value pairs from URL query strings

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Matches HTTP or HTTPS URLs and captures the protocol

Data URL

Matches data: URL scheme with optional MIME type and base64 encoding

WebSocket URL

WebSocket URL starting with ws:// or wss://