Duration / Time Elapsed Extraction Regex for JavaScript

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching duration / time elapsed extraction, 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

// Duration / Time Elapsed Extraction
// ReDoS-safe | RegexVault — Dev & Systems > Log Parsing

const durationTimeElapsedExtractionRegex = /([0-9]+(?:\.[0-9]+)?)\s*(ns|us|ms|s|m|h|min|sec|milliseconds?|microseconds?|seconds?|minutes?|hours?)\b/i;

function validateDurationTimeElapsedExtraction(input: string): boolean {
  return durationTimeElapsedExtractionRegex.test(input);
}

// Example
console.log(validateDurationTimeElapsedExtraction("completed in 125ms")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Dev & Systems > Log Parsing 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=numeric value, 2=unit. Covers nanoseconds to hours. The \b prevents partial unit matches. Parse to a canonical duration type after extraction for comparison and aggregation.