More free security tools

Threat Modeling: Model components, data flows and trust boundaries, generate STRIDE threats with mitigations, rate risk and export a Markdown report with a Mermaid diagram.
Dev Toolbox: Decode and lint JWTs, evaluate Content-Security-Policy, grade HTTP security headers and cookies, encode/hash data and scan code for leaked secrets, all locally.
Dependencies & CI: Check package-lock, yarn.lock, requirements.txt, pom.xml, go.sum and more against OSV.dev, and generate GitHub Actions for CodeQL, Dependabot, gitleaks and Trivy.
Data Lab: Chain 100+ operations into recipes: Base64, hex, URL, AES-GCM, HMAC, PBKDF2, MD5/SHA, gzip, XOR brute force, IOC extraction and defanging, with Magic auto-detect.
PKI Tools: Decode and lint X.509 certificates, chains, CSRs and CRLs, generate CSRs and keys, match keys to certificates, convert PEM/DER/P7B/JWK. Nothing is uploaded.
AI Skill Scanner: Scan SKILL.md files, agent instructions, MCP server configs and Claude Code hooks for prompt injection, data exfiltration, hidden Unicode and dangerous commands.
Website Recon: Passive recon for a domain: DNS records, SPF, DMARC, DKIM, CAA, DNSSEC, certificate transparency subdomains, RDAP registration, HSTS preload and archive history.