IPv4 Octet Extraction (Capture Groups) Regex for JavaScript

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching ipv4 octet extraction (capture groups), ported and verified for JavaScript. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your JavaScript project — whether you're validating in an Express middleware, a Next.js API route, or a client-side form.

Javascript Implementation

// IPv4 Octet Extraction (Capture Groups)
// ReDoS-safe | RegexVault — Web & Network > IPv4

const ipv4OctetExtractionCaptureGroupsRegex = /^((?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9]))\.((?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9]))\.((?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9]))\.((?:25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9][0-9]|[0-9]))$/;

function validateIpv4OctetExtractionCaptureGroups(input: string): boolean {
  return ipv4OctetExtractionCaptureGroupsRegex.test(input);
}

// Example
console.log(validateIpv4OctetExtractionCaptureGroups("192.168.1.1")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Web & Network > IPv4 category and carries a ReDoS-safe certification. That matters for JavaScript developers because especially critical in long-running Node.js event loops where a ReDoS vulnerability can block the entire process. 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

Groups 1–4 capture each octet as a string. Cast to integer after extraction. Python users can use (?P<octet1>...) syntax for named groups.