URL with Port Number Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching url with port number, ported and verified for Python. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Python project — whether you're validating in a Django view, a FastAPI endpoint, or a standalone data processing script.

Python Implementation

# URL with Port Number
# ReDoS-safe | RegexVault — Web & Network > URL

import re

url_with_port_number_pattern = re.compile(r'^https?://(?:[a-zA-Z0-9\-]+\.)+[a-zA-Z]{2,63}:(6553[0-5]|655[0-2][0-9]|65[0-4][0-9]{2}|6[0-4][0-9]{3}|[1-5][0-9]{4}|[1-9][0-9]{0,3})(?:/[^\s]*)?$')

def validate_url_with_port_number(value: str) -> bool:
    return bool(url_with_port_number_pattern.fullmatch(value))

# Example
print(validate_url_with_port_number("https://example.com:443"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Web & Network > URL category and carries a ReDoS-safe certification. That matters for Python developers because particularly important in Python web servers where CPU-bound regex operations can stall concurrent request handling. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Port range strictly enforced as 1–65535. Port 0 is excluded. Default ports (80 for HTTP, 443 for HTTPS) are not required to be present.