Decode and inspect SSL/TLS certificates directly in your browser. Paste a PEM certificate and instantly see the subject, issuer, validity dates, SANs, and all fields — no command line needed.
Open SSL Certificate Decoder → free, no sign-inReading the contents of an SSL certificate normally means running openssl x509 -text in a terminal — fine if you're comfortable with the command line, but a barrier for everyone else. The SSL Certificate Decoder takes a PEM-format certificate, parses it entirely in the browser, and displays every field in a readable layout: subject, issuer, validity window, Subject Alternative Names, signature algorithm, public key details, and extensions.
Developers and sysadmins who need to inspect a certificate's contents quickly — checking expiry dates, verifying SANs for a wildcard, or confirming an issuer — without reaching for a terminal or uploading a certificate to a third-party site.
No tutorials. No learning curve. Open it and get started.
No server uploads. Everything runs locally in your browser. Your files and data never leave your device.
Completely free. No trial period. No premium tier for basic functionality. No account required. Use it as often as you need.
One job, done well. SSL Certificate Decoder was built to solve a specific problem cleanly. No feature bloat, no ads, no distractions.
Is my certificate sent to a server?
No — decoding happens entirely in your browser. The certificate text never leaves your device.
What certificate format does it accept?
PEM format (base64-encoded, with BEGIN/END CERTIFICATE headers).
Can I decode intermediate and root certificates?
Yes — paste any certificate in PEM format.
Does it validate the certificate against a CA?
No — it decodes the content. For validation, use your browser's built-in certificate viewer or a full PKI tool.
Is this free?
Yes — free with no sign-in.
Free. Instant. No sign-in. Open it and get the job done.
Open SSL Certificate Decoder on Doathingy.com →