SecOps Tools · Detection Engineering

RegEx Lab

Live regex testing built for logs and secrets — match highlighting, capture-group inspection, substitution, flavor-aware portability linting, and a ReDoS detector that catches catastrophic backtracking. Matching runs in a sandboxed worker, so a malicious pattern can never freeze the tab.

· 100% client-side — patterns & test data never leave your browser

Test string live · debounced · highlights all matches
ReDoS & safety
Portability lint
Matches & capture groups
Saved snippets (this browser only)
Plain-English breakdown of your current pattern, token by token.

Frequently asked questions

What is ReDoS and how does the detector help?

ReDoS (Regular expression Denial of Service) happens when a pattern triggers catastrophic backtracking and hangs on certain inputs. RegEx Lab analyzes your pattern for risky constructs and warns you before they cause a problem in production.

Is my pattern or test data uploaded anywhere?

No. Everything runs in your browser. Matching executes in a sandboxed Web Worker so a malicious pattern can never freeze the tab, and neither your pattern nor your test data ever leaves your device.

Which regex flavors are supported?

It tests against the JavaScript engine and lints for portability across common flavors (PCRE, RE2, .NET, and others), flagging constructs that behave differently or are unsupported elsewhere.

What is the security pattern library?

A vetted set of 25 ready-to-use patterns for matching secrets, tokens, IPs, and other log artifacts that SOC and sysadmin work commonly needs.

KQL Builder → Sentinel & Defender XDR query builder WinEvents → Windows Event ID lookup with MITRE ATT&CK mappings TokenDecoder → JWT / SAML / OIDC token inspector