Regex Tester & Debugger

Enter a regular expression and test string to see matches highlighted in real time.

Flags

How to Use

  1. 1Enter your regular expression pattern in the regex field.
  2. 2Set flags such as global, case-insensitive, or multiline.
  3. 3Type or paste your test string in the input area.
  4. 4View highlighted matches and captured groups in the results panel.

Frequently Asked Questions

Which regex flavor does this tool use?

It uses JavaScript's built-in RegExp engine, which follows the ECMAScript specification. Most common regex features like lookaheads, character classes, and quantifiers are fully supported.

Can I see which groups my regex captures?

Yes. Each match is broken down into its numbered and named capture groups, displayed in a table below the highlighted results.

How do I make my regex case-insensitive?

Toggle the 'i' flag in the flags selector. This makes your pattern match regardless of letter case.