Regex Tester - Test Regular Expressions Online
Use this free regex tester to build and debug regular expressions in real time. Enter a pattern, choose flags, and test it against any string to see highlighted matches, capture groups, and match positions instantly.
//gi
Preview (2 matches)
Contact us at hello@example.com or support@test.org for more information.
Match Details
| # | Match | Index | Groups |
|---|---|---|---|
| 1 | hello@example.com | 14 | — |
| 2 | support@test.org | 35 | — |
How does the Regex Tester work?
This tool compiles your pattern into a native JavaScript RegExp object using the flags you select — global, case-insensitive, multiline, and dot-all — then runs it against your test string. Matches are highlighted directly in the text, and each match's index and captured groups are listed below for easy debugging.