Decode and inspect SSL/TLS certificates, fingerprints, and validity details.
Parse and analyze X.509 certificates
Paste a certificate to see its details
Get started in seconds
Export or copy a PEM-encoded certificate (-----BEGIN CERTIFICATE-----)
Paste into the input area and click Decode Certificate
Review subject, issuer, validity dates, and fingerprints
What you can do
Decode subject, issuer, serial number, and algorithms
Instant expiration status with days remaining
SHA-256 and SHA-1 certificate fingerprints
Understanding certificate structure
SSL/TLS certificates are digital documents that authenticate a website's identity and enable encrypted connections. They contain the public key, identity information, and a digital signature from a Certificate Authority (CA).
The PEM format is the most common encoding for certificates:
-----BEGIN CERTIFICATE-----
Base64-encoded certificate data
-----END CERTIFICATE-----