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SSL Certificate Decoder

Decode and inspect PEM/X.509 SSL certificates.

Free online tool. No signup required. All processing runs in your browser.

About this tool

Paste a PEM certificate or upload a file to view details such as subject, issuer, expiration dates, and extensions.

What is SSL Certificate Decoder?

SSL/TLS certificates are X.509 documents that bind a public key to a domain. They are commonly stored in PEM format.

How to use SSL Certificate Decoder

  1. Paste PEM content or upload a certificate.
  2. View decoded fields like issuer and validity.
  3. Inspect extensions such as SANs if needed.

Examples

Example input

-----BEGIN CERTIFICATE-----
MIID...
-----END CERTIFICATE-----

Example output

Subject: CN=example.com, Issuer: CN=CA, Valid: 2024-01-01 to 2025-01-01

FAQ

What is PEM format?
A Base64 encoded certificate wrapped with BEGIN/END markers.
Can I decode multiple certificates?
Some tools support chains with multiple PEM blocks.
Are these tools free?
Yes. All tools on DevToolsHub are free to use.
Does the tool store my data?
No. Processing happens in your browser. We do not store or send your input to any server.
Can I use the output in production?
Yes. Use the result as you like; we do not claim any rights over the output.

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