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X.509 certificate and CSR inspector
Paste a PEM certificate or PKCS#10 CSR — subject, issuer, validity window, SANs, key facts, and extensions, parsed by pkijs in your tab. Nothing fetched, nothing uploaded.
- No chain validation — that needs trusted root stores and revocation data (OCSP/CRL) this offline page refuses to contact.
- “Valid now” means the validity window contains your clock — never that anyone trusts the certificate.
- No private key handling: paste a certificate or CSR, and a CSR’s whole point is that the private key never left your machine.
Nothing in yet
Paste, drop, or type to begin. Everything stays on this device.
paste a certificate or CSR PEM