PEM / Certificate Inspector
Identify PEM blocks and inspect X.509 certificates (subject, issuer, validity, SAN, key) and ASN.1 — no verification.
About this tool
Paste a PEM certificate or public key to see its subject, issuer, validity dates, key type, alternative names and fingerprint, with an outline of its ASN.1 structure. Base64 or hex DER also works.
The certificate is not verified or checked against a chain. A private key is refused and not read at all. Everything is decoded in your browser, and at most 200,000 characters are read.