Free Developer Tools

Free Security Tools

Fast, passive, privacy-respecting checks to find issues in your apps — no signup, no install. Built by the ZeroSight360 security team.

Decode a JWT header and payload and flag security issues — alg:none, weak HMAC, missing expiry, sensitive claims. Runs entirely in your browser.

Enter a URL and get a graded report on CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, and cookie flags.

Paste a Content-Security-Policy and get a directive-by-directive grade with fixes for unsafe-inline, unsafe-eval, and missing protections.

Find out whether your domain can be spoofed: SPF, DKIM and DMARC posture with a clear grade and exact fixes. Passive DNS lookups only.

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