Dev / ITnew

Regex Tester

Free online regex tester and regular expression editor with real-time match highlighting. Test, debug, and build regular expressions with instant feedback. See all matches highlighted in your test string, view capture groups and named groups, and use replace mode with $1 $2 group references. Includes 25+ preset patterns for common use cases like email, URL, IPv4, Thai ID, phone numbers, dates, hex colors, and more. Supports all JavaScript regex flags: global, case-insensitive, multiline, dotAll.

PRESETS

//g
test string
0 chars

how to use

  1. 1.Enter your regular expression in the pattern field
  2. 2.Set flags (g, i, m, s) as needed using the toggle buttons
  3. 3.Paste your test string in the input area
  4. 4.Matches are highlighted in real time with match details below

frequently asked

Which regex flavor does this tool use?

This tool uses JavaScript (ECMAScript) regex syntax, compatible with Node.js, browsers, and most modern languages.

What does the global (g) flag do?

The global flag finds all matches in the string. Without it, only the first match is returned.