Regex Tester Online

Test and debug regular expressions online with live match highlighting. Supports all JavaScript regex flags. Free regex tester — see matches and match count instantly.

Live Highlighting All JS Flags Match Count Group Support Free
Regular Expression Pattern
Flags (g, i, m, s)
Test String Matches — highlighted in gold
Quick reference
What it is
  • A live regex tester that highlights matches in your text as you type the pattern — using JavaScript's built-in RegExp engine.
How to use it
  • Enter your pattern in the Pattern field
  • Set flags — g = global, i = case-insensitive
  • Paste your test text below
  • Matches appear highlighted in gold automatically
When you need this
  • Validating email, phone, or postal code formats
  • Extracting data from a log file or text
  • Testing a regex before putting it in your code
  • Debugging why a pattern matches too much or too little
Good to know
  • g flag finds all matches — without it, only the first match is found
  • i flag makes matching case-insensitive
  • Use .*? instead of .* to avoid greedy over-matching
  • Escape special characters like . and * with a backslash
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