Decode SSL/TLS certificates from PEM format. Reveals subject, issuer, validity dates, SANs, public key details, and all certificate fields.
Open SSL Certificate Decoder → free, no sign-inSSL/TLS certificates in PEM format are Base64-encoded blobs that contain critical information — issuer, subject, expiry dates, Subject Alternative Names, public key details. Reading them requires decoding. The SSL Certificate Decoder takes a PEM certificate, decodes it, and presents all the critical fields in a clear, readable layout.
Developers configuring SSL certificates, system administrators auditing certificates before expiry, anyone who needs to quickly check what a certificate contains without running openssl commands.
No tutorials. No learning curve. Open it and get started.
No server uploads. No command-line tools required — paste the PEM and get all certificate details displayed clearly.
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.
Where do I get my PEM certificate?
From your hosting provider, certificate authority, or by running: openssl s_client -connect yourdomain.com:443 | openssl x509 -text
What are Subject Alternative Names?
SANs list all the domain names the certificate is valid for — important for multi-domain and wildcard certificates.
What is certificate expiry?
The Not After date — after which the certificate is invalid and browsers will show security warnings.
Can I check certificate chain?
This tool decodes a single certificate — for chain validation, use SSL checking services.
Is my certificate data sent anywhere?
No — decoding runs locally.
Free. Instant. No sign-in. Open it and get the job done.
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