Which regex flavor is used?

Regex Tester & Matcher

Popular Runs in Your Browser

Test JavaScript RegExp patterns with instant visual match highlighting, capture group extraction, match counts, flag toggles (g, i, m, s), and common regex presets.

Browser-based: this tool works on your device and does not send your input to an Alona Tool server. See the Privacy Policy for details.

Fast Processing

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Example Usage & Test Cases

Email matcher

Input Scenario:

Pattern: [\w.-]+@[\w.-]+\.\w+, Flags: gi

Generated Result:

Highlights all matching emails with capture group breakdown

How It Works

Executes the native browser RegExp engine directly against your test string with boundary safeguards.

Frequently Asked Questions

The native ECMAScript / JavaScript regular expression engine.

Good to Know

Common uses

Trying a pattern against sample text before using it in code

Limitations and notes

Uses your browser's JavaScript regex engine; other languages can behave differently (for example with lookbehind or named groups).

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Interactive JavaScript Regular Expression Tester

Test and debug complex pattern matching with instant color-coded capture group analysis.

Key Highlights:

Real-time match highlighting
Capture groups table
Pre-built patterns (Email, URL, IP, Phone, Dates)
Regex flags control