What is a regular expression?

A regular expression (regex) is a sequence of characters that defines a search pattern. It is used for pattern matching in strings — extracting data, validating input, finding and replacing text. Common uses include email validation, phone number extraction, and log file parsing.

What do regex flags like g, i, m mean?

Common regex flags: g (global) finds all matches, not just the first; i (case-insensitive) ignores uppercase/lowercase differences; m (multiline) changes ^ and $ to match line boundaries instead of string boundaries. You can combine flags like /pattern/gi.

How do I test a regex pattern?

Type your regex pattern between the forward slashes in the pattern input, add any flags you need, then type a test string. Valid matches will be highlighted instantly. Use common patterns like \d+ for digits, \w+ for word characters, and .* for any characters.

Developer

Regex Tester

Test and debug regular expressions with real-time matching.

Pattern

Enter your regular expression

Flags

Global (g)

Case Insensitive (i)

Multiline (m)

Test String

Enter text to test against the pattern

Documentation

How to Use

Enter regex pattern

Type your regular expression in the input field.

Enter test string

Paste or type the text you want to test against.

View matches

See highlighted matches in real-time.

Pro Tips

Use flags for case-insensitive matching

Test edge cases

Examples

Input

[a-z]+@[a-z]+\.[a-z]+

Output

Matches: test@example.com

Regex Tester

How to Use

Enter regex pattern

Enter test string

View matches

Examples

FAQ

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