Regex Tester: Test Regular Expressions Online with Live Matching

Regular expressions are powerful but tricky. Our tester lets you write regex patterns and instantly see matches highlighted in your test string, with capture group details and flag options — all running locally in JavaScript.

How to Use Regex Tester

• 1.

  Enter your regex pattern

• 2.

  Set flags (global, case-insensitive, multiline, etc.)

• 3.

  Type or paste your test string

• 4.

  See matches highlighted in real-time with group details

Key Features

• Live match highlighting as you type
• Capture group inspection
• All JavaScript regex flags supported
• Match count and position information
• Common regex patterns reference

When to Use This Tool

• •

  Developing regex for form validation

• •

  Testing patterns for data extraction

• •

  Learning regex with immediate feedback

• •

  Debugging complex patterns step by step

Frequently Asked Questions