UtilityKit

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Regex Tester

Test regular expressions with live matches

About Regex Tester

Regex Tester in UtilityKit is a fast, free browser-based tool designed to solve one job clearly: test regular expressions with live matches. It is built for quick results with no sign-up, clean output, and practical defaults so you can finish your task in seconds and move on. Use it for daily workflows, one-off fixes, and shareable links when you need reliable output without installing extra software.

Why use Regex Tester

  • Debug complex regex patterns before putting them into code.
  • Learn how different regex flags (g, i, m) affect matches.
  • Visual feedback makes regex much easier to understand.

How to use Regex Tester

  1. Enter your regular expression at the top.
  2. Provide the test string in the main editor.
  3. Matches and capture groups will be highlighted instantly.

When to use Regex Tester

  • When you need a quick regex tester result without installing software.
  • When you are validating or transforming data before sharing it with teammates.
  • When you want a repeatable, low-friction workflow from any device.

Frequently Asked Questions

Which regex flavor is used?

This tool uses the JavaScript (ECMAScript) regular expression engine built into your browser.

Does it support lookbehinds?

Yes, modern browsers support lookaheads and lookbehinds in JavaScript regex.

Is Regex Tester free to use?

Yes. Regex Tester is free to use in UtilityKit with no signup required.

Do I need to install anything to use Regex Tester?

No installation is needed. Open the tool in your browser and use it directly.

Can I use Regex Tester on mobile?

Yes. The tool is designed to work on modern mobile and desktop browsers.

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