Test and debug regular expressions in real-time
Regular expressions (regex) are patterns used to match character combinations in strings. A regex tester lets you write a pattern and test it against sample text in real-time, showing which parts match and why.
Regex is supported by virtually every programming language and is essential for form validation, data extraction, search-and-replace operations, and text parsing.
Flags modify how the regex engine processes your pattern: g (global) finds all matches instead of just the first one, i (case-insensitive) ignores letter case, m (multiline) treats ^ and $ as per-line anchors, s (dotall) makes . match newlines, and u (unicode) enables full Unicode support.
Enter your regex pattern between the slashes and select the appropriate flags (g, i, m, s, u). Type your test string in the text area below. The tool highlights all matches in real-time and shows match details including positions and capture groups.
Click the 'i' button to see a quick reference guide for regex syntax including anchors, character classes, quantifiers, and groups.