Real DER/ASN.1 parsing — browser-only

PEM Certificate Viewer

Paste or upload a PEM-encoded X.509 certificate to decode its fields: subject, issuer, validity, public key, extensions, and real SHA fingerprints — computed from the actual DER bytes.

X.509DER/ASN.1SHA-1 fingerprintSHA-256 fingerprintExtensions

Real parsing

Fingerprints are computed with crypto.subtle.digest on the raw DER bytes — not mocked or estimated.

Input

Paste your PEM.

Upload .pem / .crt

Supported formats

• X.509 Certificates (CERTIFICATE)

• Base64-encoded DER within PEM headers

• Self-signed, CA, and leaf certificates

Parsed certificate fields will appear here.

Click Load ISRG Root X1 to try a real CA certificate.

Related Tools

X.509 Certificate Viewer — PEM Certificate Parser

Inspect PEM-encoded X.509 certificates: subject, issuer, validity dates, SANs, and fingerprint.

CSR Decoder — Certificate Signing Request Parser

Decode and inspect PEM-encoded Certificate Signing Requests to view subject details and public key info.