Regex Tester

Test and debug regular expressions with live highlighting

What is Regex?

Regular expressions (regex) are patterns used to match character combinations in strings. They’re supported by virtually every programming language and used heavily in text processing, validation, and search operations.

How to Use

  1. Enter your regex pattern in the pattern field
  2. Set flags (g, i, m, etc.)
  3. Type or paste your test string
  4. View matches highlighted in real-time

Common Regex Patterns

PatternDescription
\d+One or more digits
[a-zA-Z]+One or more letters
\b\w+@\w+\.\w+\bSimple email
https?://\S+URL
\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\bIPv4 address

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Frequently Asked Questions

What is a regular expression?

A regular expression (regex) is a sequence of characters that defines a search pattern. It's used for pattern matching, text search, and string manipulation in programming languages.

What regex flags are supported?

This tool supports JavaScript regex flags: g (global), i (case-insensitive), m (multiline), s (dotAll), and u (unicode).

Is my data safe?

Yes. All regex testing happens in your browser. No data is sent to any server.