Regex Tester & Debugger
Test, debug, and execute regular expressions against text strings in real-time.
Regular Expression
/
/
Invalid Regular Expression
Test String
Highlighted Matches
Extracted Matches
0 Matches
How To Use
Write Pattern: Type your regex in the top input bar. Do not include the leading/trailing slashes (/).
Set Flags: Add flags in the rightmost box. Common flags are
g (global search), i (case-insensitive), and m (multi-line).Test String: Paste your text in the left textarea. Matches will be instantly highlighted in yellow on the right.
Why Use This Tool?
Real-Time Feedback: See exactly what your regex is matching as you type. No need to click submit or refresh the page.
Pre-Built Cheatsheet: Quickly grab common regex patterns for emails, URLs, dates, and IPs using the dropdown menu.
100% Offline Privacy: Everything runs locally in your browser using JavaScript's native RegExp engine. Your data is perfectly secure.
Frequently Asked Questions
Which regex engine does this tool use?
This tool uses the native JavaScript RegExp engine built into your browser. It fully supports standard JS regex syntax, including lookaheads, lookbehinds, and named capture groups.
What do the 'g', 'i', and 'm' flags do?
g (global): Finds all matches rather than stopping after the first match.
i (ignore case): Makes the regex case-insensitive (A matches a).
m (multiline): Changes the behavior of ^ and $ to match the start and end of each line, instead of the whole string.