# Regex Tester & Explainer

Test, debug, and explain JavaScript regular expressions online with live match highlighting, capture group extraction, and replacement mode directly in your browser with zero server uploads.

## URL
https://codeasystem.com/tools/developer/regex-tester/

## Features
- Real-time regular expression evaluation
- Support for standard flags: `g` (global), `i` (case-insensitive), `m` (multiline), `s` (dotAll), `u` (unicode)
- Live list of match indices, lengths, and captured sub-groups
- Interactive string replacement mode with `$1`, `$&` token substitution
- Preset library for email, URL, IPv4, date, hex colors, and UUIDs
- 100% browser-based processing (zero server uploads)

## Privacy
All processing happens directly in your browser using client-side JavaScript. Your regex patterns and test strings are never uploaded to any server or third-party service.