YurlieRegex Tester & Debugger
Test and debug regular expressions with live match highlighting and capture group extraction.
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gExamples:
Common Regex Cheat Sheet & Patterns
| Use Case | Regex Pattern | Description |
|---|---|---|
| Email Address | ^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$ | Standard email format validation |
| URL Format | https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b | Matches HTTP & HTTPS URLs |
| IPv4 Address | ^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$ | Matches standard IPv4 addresses |
| UUID (v4/v7) | ^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$ | 36-character hyphenated UUID pattern |
Frequently Asked Questions
What is a Regular Expression (Regex)?
A Regular Expression (Regex) is a sequence of characters that forms a search pattern used for text matching, string validation, searching, and replacing operations in programming languages.
What do the regex flags (g, i, m, s, u, y) mean?
Flags modify pattern matching behavior: "g" performs global matching across the whole string, "i" makes matching case-insensitive, "m" enables multiline anchors (^ and $ match line boundaries), and "s" allows the dot (.) to match newlines.
Does this Regex Tester send my text or patterns to a server?
No. All regular expression matching and capture group extraction run 100% locally in your browser using the JavaScript RegExp engine. Your input strings never leave your device.