Regex Tester

Test regular expressions live — highlighted matches, capture groups and a replace preview. This tool runs 100% in your browser — nothing is uploaded or saved.

How to use

1. Type your regular expression pattern and tick the flags you need (g, i, m, s).
2. Paste or type test text — matches highlight instantly and the count updates live.
3. Check the list below for each match and its capture groups.
4. Optionally type a replacement (use $1, $2 for groups) to preview the replaced text, then copy it.