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Regex Tester
Test regular expressions with live match highlighting and detailed match info. Runs entirely in your browser — nothing is uploaded.
Regex & Test String
Results
Common Regex Patterns
\\d+
Matches one or more digits (0-9).
\\w+
Matches one or more word characters (a-z, A-Z, 0-9, _).
[a-zA-Z0-9._%+-]+@[a-z]+\\.[a-z]{2,}
Basic email validation pattern.
https?://[^\\s]+
Matches HTTP and HTTPS URLs.
Frequently Asked Questions
What is a regular expression?
A regular expression (regex) is a pattern used to match character combinations in strings. Regex is used in search, replace, validation, and data extraction across programming languages and text editors.
What are regex flags?
Flags modify regex behavior: g (global — match all occurrences), i (case-insensitive), m (multiline — ^ and $ match line boundaries), and s (dotAll — dot matches newlines).
How do I learn regex?
Start with common patterns: . (any char), * (zero or more), + (one or more), \\d (digit), \\w (word char). Practice with this tool by testing patterns against sample text.