Regex Tester
Test and debug regular expressions with real-time matching, highlighting, and capture group support.
How to Use
Enter your regular expression pattern in the pattern input.
Set the flags you need (global, case-insensitive, multiline, etc.).
Type or paste your test string in the text area.
Matches are highlighted in real time. Capture groups are shown below.
Frequently Asked Questions
What regex flavor does this use?
This tool uses JavaScript's built-in RegExp engine. It supports standard regex syntax including character classes, quantifiers, lookaheads, lookbehinds (in modern browsers), and named capture groups.
What do the flags mean?
g = global (find all matches), i = case-insensitive, m = multiline (^ and $ match line boundaries), s = dotAll (. matches newlines), u = unicode.
Can I test regex for other languages?
JavaScript regex is very similar to regex in most languages (Python, Java, PHP, etc.). However, some features may differ. This tool tests JavaScript regex specifically.