Real-time regex testing with security-focused presets: IPv4, IPv6, hashes, secrets, IOCs. Live match highlighting, captured-group inspection, replacement preview. Client-side, no backend, no data leaves your browser.
Pattern
Security Presets (click to load)
Test Input
Output
0matches
0captured
0ms
Enter a pattern and test data to see matches.
Replacement will appear here.
Captured Groups (per match)
Capturing groups will appear here for each match.
JavaScript regex engine (V8 in Chrome / SpiderMonkey in Firefox). Behaves slightly differently from PCRE, RE2, or .NET regex. Negative-width lookbehind support varies by browser version.
Built-in security presets cover the common patterns: IPv4, IPv6, MD5/SHA1/SHA256, JWT, AWS access key, GitHub token, Slack token, base64 PEM blocks, MAC address, domain, email, URL with credentials, hex-encoded payload. Adapt to your environment.