Decode X.509 Certificates

Decode and inspect a TLS or SSL certificate right in your browser.

Private and secure: Your certificate never leaves your device.

All X.509 certs will:

  • Start with —–BEGIN CERTIFICATE—–
  • Contain valid base64
  • Decode to a valid ASN.1 sequence
  • End with —–END CERTIFICATE—–

Paste your PEM-encoded certificate below and get a full breakdown.

Decode Certificate

To try via OpenSSL commands on your local machine:

# read from a file 
openssl x509 -in your-cert.pem -text -noout

# read from stdin
cat your-cert.pem  | openssl x509  -text -noout