Find catastrophic backtracking, portability errors, injection risks, and correctness bugs in regex patterns — before they reach production.
One badly-nested quantifier can freeze an entire server for minutes. One unescaped user input can turn a search into a denial-of-service attack. Most regex reviews catch obvious syntax errors — they miss the catastrophic backtracking, the injection vectors, and the portability traps hiding in your patterns. RegexGuard scans every pattern for safety, correctness, and maintainability so your regex never becomes the bottleneck.
90 checks across 6 categories, covering every aspect of regex safety, correctness, and maintainability.
Detects nested quantifiers, exponential state explosion, unbounded repetition groups, overlapping alternations, and patterns that can freeze your server for minutes on adversarial input strings.
Finds engine-specific features that break across JavaScript, Python, Go, and Java. Catches lookbehind incompatibilities, named group syntax mismatches, flag differences, and Unicode property escapes.
Catches unescaped metacharacters, incorrect character class ranges, misplaced anchors, redundant groups, empty alternation branches, and patterns that silently match nothing or everything.
Flags overly complex patterns exceeding cognitive thresholds, deeply nested groups, magic numbers in quantifiers, missing comments on complex expressions, and patterns that no human can review.
Detects missing start/end anchors on validation patterns, partial match vulnerabilities in security contexts, multiline anchor confusion, and patterns that validate less than developers expect.
Finds user input concatenated into RegExp constructors, template literal injection points, missing regex escaping on dynamic values, and patterns built from untrusted sources without sanitization.
Purpose-built for regex safety and correctness. Not a generic linter with a couple regex rules.
| Capability | RegexGuard | Manual Review | ESLint | SonarQube | regex101 |
|---|---|---|---|---|---|
| Catastrophic backtracking detection | ✓ 15 rules | Ad hoc | ✗ | Partial | Partial |
| Cross-engine portability | ✓ 15 rules | Ad hoc | ✗ | ✗ | Partial |
| Correctness analysis | ✓ 15 rules | Ad hoc | Partial | Partial | ✗ |
| Pattern injection detection | ✓ 15 rules | ✗ | ✗ | Partial | ✗ |
| Anchoring analysis | ✓ 15 rules | Ad hoc | ✗ | ✗ | ✗ |
| Maintainability scoring | ✓ 15 rules | Ad hoc | ✗ | Partial | ✗ |
| Static analysis (no runtime) | ✓ | ✓ | ✓ | ✓ | ✗ |
| 100% local / zero telemetry | ✓ | ✓ | ✓ | ✗ | ✗ |
| Score & grading system | ✓ | ✗ | ✗ | ✓ | ✗ |
| Zero configuration | ✓ | N/A | ✗ | ✗ | ✓ |
Start scanning for free. Upgrade when your patterns demand it.
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Install RegexGuard in 30 seconds. Find every backtracking bomb, injection vector, and correctness bug before your users find them for you.