Regex Tester & Debugger
Test Regular Expressions in real-time, highlight matches with color codes, and inspect captured groups.
Match ResultsNo matches found
How to Use the Regex Tester?
1
Type your regular expression into the pattern input field.
2
Toggle regex flags like 'g', 'i', or 'm' according to your needs.
3
Paste or type your test string; all matching substrings highlight instantly in real-time.
4
Switch to the 'Replace' tab to simulate substitutions with $1, $2 capture groups.
Is my test data uploaded to a server?
No! All regex compilation, evaluation, and substitutions run 100% locally in your browser's JavaScript engine.
Which regex syntax is supported?
Standard ECMAScript (JavaScript) regular expressions with all modern flags (g, i, m, s, u).