Regex Tester

Test regular expressions against text with real-time match highlighting. All processing happens client-side -- your data never leaves your browser.

//g
Flags:
Matches will be highlighted here...

How to Use the Regex Tester

  1. Enter your regular expression pattern in the pattern input field.
  2. Select the flags you need: global (g), case-insensitive (i), multiline (m), or dotAll (s).
  3. Type or paste your test string into the text area below.
  4. Matches are highlighted in real-time with full details including capture groups.

Supported Flags

  • g (global) -- Find all matches rather than stopping after the first
  • i (case-insensitive) -- Match letters regardless of case
  • m (multiline) -- ^ and $ match the start/end of each line
  • s (dotAll) -- Dot (.) also matches newline characters

Features

  • Real-time match highlighting as you type
  • Capture group extraction with index positions
  • Named capture group support
  • Graceful error handling for invalid patterns
  • 100% client-side processing for full privacy
  • No data stored, no sign-up required