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Regular Expression Tester – Test Regex Patterns Online

Test regex patterns with live highlighting, match details, and flag support—perfect for validating email, phone, and URL patterns.

🟢 Runs locally · no uploads

Regex Tester

Test and debug regular expressions

code Regular Expression
\d{3}-\d{3}-\d{4}
edit_note Test String
Call me at 555-123-4567 or 555-987-6543
check_circle Matches
search
No matches found
Flags:

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› About this tool · FAQ

Stop debugging regex in console! Test regular expressions instantly with real-time pattern matching, capture group analysis, replace/split modes, and detailed pattern explanations. Supports all JavaScript regex features including flags, lookaheads, and named groups. Perfect for validation, parsing, and text manipulation. Free, works offline, unlimited testing.

What regex flags are supported?

All JavaScript regex flags: global (g), ignore case (i), multiline (m), dotAll (s), unicode (u), and sticky (y). Each flag can be toggled individually.

How do I test against multiple inputs?

Enable "Test Multiple Inputs" and enter each test string on a separate line. The tool will test your pattern against all inputs and show results for each.

Can I see capture groups?

Yes! Enable "Show Groups" to see both numbered capture groups and named groups. The tool displays the content of each group for every match.

What test modes are available?

Four modes: Test (boolean match), Match (find matches), Replace (substitute text), and Split (divide text). Each mode provides different output and functionality.

How does pattern explanation work?

The tool analyzes your regex pattern and explains common components like anchors, quantifiers, character classes, and other regex elements.