DevTools
Language

Regex Debugger

DevTools Regex Debugger tests regular expressions locally in your browser with real-time match highlighting, capture groups, and match indices—supports g/i/m/s/u/y flags.

Regex Debugger

Enter a regex and test text to highlight matches in real time, view capture groups, and inspect match indices.

Flags
Match highlights
Order date 2024-06-15, ship date 2024-06-18, amount 299.00

2 matches · /\d{4}-\d{2}-\d{2}/g

  • #1 "2024-06-15" @ index 11

  • #2 "2024-06-18" @ index 33

Tip: use named captures like (?<date>YYYY-MM-DD) to see named groups. The g flag lists all matches.

About this tool

Enter a pattern and test text. Matches are highlighted; capture groups and indices are listed—ideal for writing and debugging complex regex.

How to use

  1. Enter a regex pattern and flags.
  2. Paste test text.
  3. Review highlighted matches and the group list.

FAQ

How does the regex debugger highlight matches?

After you enter a pattern and text, matched spans are highlighted in the test area with emphasis styling.

Are named capture groups supported?

Yes. With (?<name>...) syntax, named groups appear separately in the match list with their values.

How is this different from the Regex Generator?

Regex Generator provides preset patterns for Email, URL, UUID, and more. Regex Debugger tests any custom pattern with visual highlighting and group details.

Is my text uploaded?

No. Matching runs locally in your browser.

Related tools