Certificate Decoder

Paste your PEM-encoded SSL/TLS certificate to instantly decode and view all fields — validity dates, subject, issuer, SANs, key info, and fingerprints.

100% Free No Registration SHA-256 Fingerprint

Paste SSL Certificate (PEM format)

Validity DatesFrom, until and days remaining

FingerprintsSHA-256 and SHA-1

SANs DecodedAll alternative names listed

Key InfoType, algorithm, and bit size

Secure by designYour certificate data is processed instantly over an encrypted connection and never stored on our servers.

Encrypted in transitSubmitted over HTTPS/TLS — nothing is sent in plain text.

Never storedDecoded certificate data is not saved to any database or log.

No third-party sharingCertificate contents are never shared with ads, trackers, or outside services.

Processed instantlyParsed on request and discarded immediately after the response.

About Certificate Decoder

What Is a Certificate Decoder?

A certificate decoder reads an SSL/TLS certificate's encoded content and displays it in human-readable form — issuer, validity dates, domain names covered, and key details — useful for verifying a certificate before or after installation without command-line tools.

How to Use the Certificate Decoder

Paste your certificate text
Click Decode
Review the decoded issuer, validity, and domain details

Key Features

Full certificate breakdown — issuer, expiration, and covered domains
No OpenSSL command line needed

Who Uses This Tool

System administrators verify certificate details before deployment. Developers troubleshoot SSL issues by checking exactly what a certificate contains.

Frequently Asked Questions

What should I check on a newly issued certificate?
Confirm the domain names covered, expiration date, and issuer match what you expect before deploying it live.

Is this tool free?
Yes, decoding a certificate is completely free.

Frequently Asked Questions

What is a PEM certificate?

PEM (Privacy-Enhanced Mail) is the most common SSL certificate format. It is a Base64-encoded DER certificate wrapped between -----BEGIN CERTIFICATE----- and -----END CERTIFICATE----- markers. Most web servers and CAs provide certificates in PEM format.

Where can I find my SSL certificate?

Your certificate is saved on your server at the path specified during installation. In cPanel it is under SSL/TLS Manager. Your CA also emails it on issuance. You can also copy it from a browser by clicking the padlock icon and exporting the certificate.

What is a certificate fingerprint?

A fingerprint is a cryptographic hash (SHA-256 or SHA-1) of the certificate contents. It uniquely identifies a certificate and lets you verify you received the correct one — any modification changes the fingerprint completely.

What does the serial number mean?

The serial number is a unique identifier assigned by the Certificate Authority. It is used for certificate revocation — when a CA revokes a cert, they add its serial to their CRL (Certificate Revocation List) or OCSP database.