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SSL Certificate Decoder

Paste a PEM SSL certificate and decode it to see subject, issuer, validity dates, Subject Alternative Names, and key type. Client-side decoding.

  • 100% free
  • No signup
  • Runs in your browser
Common uses: ssl certificate decoder · pem certificate decoder · decode ssl certificate · x509 certificate parser · ssl cert viewer

Used 35.0K times today

Paste a PEM-format SSL certificate (including the BEGIN/END lines). Basic field extraction runs entirely in your browser.

How to Use SSL Certificate Decoder

  1. 1

    Paste your PEM certificate

    Copy your certificate including the BEGIN CERTIFICATE and END CERTIFICATE lines and paste it into the input.

  2. 2

    Click Decode

    The tool parses the certificate and extracts all key fields.

  3. 3

    Review the certificate details

    See the subject, issuer, validity period, SANs, and public key algorithm.

Frequently Asked Questions

What is a PEM certificate?
PEM is a base64-encoded format for SSL/TLS certificates, typically starting with -----BEGIN CERTIFICATE-----.
Is my certificate data private?
Yes. All decoding happens in your browser. The certificate content is never sent to any server.

Embed This Tool

Add this tool to your website for free. Just copy and paste the code below:

<iframe src="https://utilko.com/embed/ssl-certificate-decoder/" width="100%" height="500" frameborder="0" title="SSL Certificate Decoder"></iframe>

About SSL Certificate Decoder

The SSL Certificate Decoder on Utilko parses PEM-format X.509 certificates in your browser and displays the subject, issuer, expiry date, and Subject Alternative Names in human-readable form — no server required.

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