Regex ReDoS Detector

Regular expression denial of service (ReDoS) is a critical security vulnerability where a malicious regex pattern causes exponential backtracking, consuming CPU resources and freezing applications. This tool analyzes your regular expressions to detect potential catastrophic backtracking vulnerabilities that could be exploited in attacks or cause performance degradation in production systems.

Simply paste your regex pattern into the analyzer and the tool will evaluate it against known ReDoS vulnerability patterns and test cases. It identifies nested quantifiers, alternation constructs, and other dangerous patterns that may lead to exponential time complexity. The detailed report shows which parts of your regex are problematic and suggests structural improvements.

This detector is essential for developers building input validation, content filtering, or any system that processes user-supplied regex patterns. Even experienced programmers can accidentally write vulnerable patterns—this tool catches those mistakes before they cause real-world outages. Use it as part of your code review process whenever regex is involved.