// free ai tool
Regex Generator & Tester
Create, test, and debug regular expressions with real-time matching and AI-powered explanations.
Regular Expression Tool
Common Regex Patterns
Validation Patterns
- Email:
^\S+@\S+\.\S+$ - Phone:
^(+d{1,3}[- ]?)?d{10}$ - URL:
^(https?|ftp):\/\/[^\s/$.?#].[^\s]*$
Extraction Patterns
- Hashtags:
#\w+ - HTML tags:
<([a-z]+)([^<]+)*(?:>([^<]*)<\/\1>)? - Dates:
\d4-\d2-\d2
Regex Best Practices
- Use comments and whitespace for complex patterns (
(?x)flag) - Prefer specific character classes (
\d) over generic ones (.) - Use non-capturing groups
(?:...)when you don't need to capture the match - Be mindful of greedy vs lazy quantifiers (
*?vs*) - Test with both matching and non-matching strings