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Free security tools

No signup. Calculators run in your browser. Scanners send one passive request.

Open the CVSS calculator Check your security headers

Calculators

Score and budget tools for triage, reporting, and program planning.

Scanners

Passive checks against a public URL or domain, with a grade and fixes.

Security Headers Checker
Grade a site's HTTP security headers and get the fixes
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SSL/TLS Checker
Check a certificate, its expiry, chain, and TLS protocol support
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Email Security Checker
Check SPF, DMARC, DKIM, MTA-STS, and BIMI records for a domain
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Subdomain Finder
Discover the subdomains of any domain from passive sources
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CORS Checker
Test a URL for CORS misconfigurations that expose data to any origin
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Analyzers

Decode and inspect tokens, headers, and payloads in your browser.

JWT Decoder & Analyzer
Decode JWTs and spot weak algorithms, expiry, and secrets
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Vulnerability data

Reference pages that the tools link into.

CVE Database
Every CVE with CVSS, EPSS, CISA KEV status, affected software, and fix guidance.
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