What is a regular expression?

A regular expression (regex) is a pattern used to match, find, and replace text. It's powerful for text processing and validation.

How do I write a regex pattern?

Regex syntax includes character classes [abc], quantifiers *, +, ?, |, anchors ^$, and groups (). Learn patterns for your specific use case.

Yes, this tool lets you enter a regex pattern and test text to see matches in real-time.

Common flags include g (global), i (case-insensitive), m (multiline), and s (dotall), depending on the regex engine.

Regular expressions are used in most programming languages, text editors, and search tools for pattern matching and validation.

Test regular expressions with real-time matching and pattern validation

Common Patterns:

Regular Expression:

/ /

Test Text:

Maximum 10,000 characters.

Matching Results:

0 Matches Found

Test and validate regular expressions in real-time

Support for global, case-insensitive, and multiline flags

View all matches and captured groups

Perfect for developers testing patterns for validation

Real-time Testing: Patterns are tested instantly as you type
Common Regex Patterns:
- [a-z]+ - One or more lowercase letters
- \d{3}-\d{3}-\d{4} - Phone number format
- \S+@\S+\.\S+ - Email pattern
- ^[A-Z] - Starts with uppercase letter
- \b\w{4}\b - Exactly 4-letter words
Flags:
- g - Global: find all matches (not just first)
- i - Case insensitive: ignore upper/lowercase
- m - Multiline: treat ^ and $ as line boundaries
Highlighting: Matched text is highlighted in the results for easy identification
Match Count: See exactly how many matches were found