Regex Tester

Overview

An online IDE for testing and debugging regular expressions. It highlights matches instantly, breaks down capture groups, and lets you toggle matching flags (global, case-insensitive, multi-line) — all running locally in your browser. A built-in cheatsheet helps you remember the right symbols.

Key features

• •Real-time regex match highlighting in your test strings
• •Detailed capture groups breakdown with indexed table
• •Configurable matching flags (g, i, m, s, u, y)
• •Pre-compiled cheatsheet for common patterns (emails, IPs, dates)
• •Client-side execution with zero external analytics

How to use

1. 1
   Enter your regex pattern in the top field.
2. 2
   Paste your test string into the body textarea.
3. 3
   Check the matching flag boxes (Global, Case Insensitive, etc).
4. 4
   Review the highlighted matches and the capture groups table.
5. 5
   Use the cheatsheet panel to construct or debug your expression.

Frequently asked questions