How to Test Regex Patterns Online

Regular Expressions: A Developer's Swiss Army Knife

Regex is one of the most powerful text processing tools available. It can validate emails, extract data from logs, find and replace patterns, and much more.

Testing Before Deploying

Always test regex patterns before putting them in production code. Edge cases can cause catastrophic backtracking, security vulnerabilities (ReDoS), or incorrect matches.

Common Regex Patterns

Email validation: ^[\w.+-]+@[\w-]+\.[\w.]+$

URL matching: https?://[\w.-]+(?:\.[\w]+)+[/\w.-]*

IP address: \b\d{1,3}(?:\.\d{1,3}){3}\b