Decode & Inspect SSL / X.509 Certificates
Parse PEM/CRT SSL certificates to view Common Name (CN), Issuer, Subject Alternative Names (SAN), and Expiration.
About This Tool
SSL / X.509 Certificate Inspector decodes raw PEM certificate blocks (-----BEGIN CERTIFICATE-----) to reveal certificate metadata, issuer authority, validity dates, days remaining, and SAN domains without requiring OpenSSL CLI.
Key Features
Decodes Common Name (CN) and Issuer
Displays validity start and expiration dates
Calculates days remaining with status badge
Lists Subject Alternative Names (SAN)
How to Use
- 1Paste your PEM-formatted certificate block or click 'Load Sample Cert'.
- 2Click 'Inspect Certificate' to extract details.
- 3Review the Common Name, Issuer, Expiry status pill, and SAN domains.
Why Use ToolSnippet SSL / X.509 Certificate Inspector?
Quickly check certificate expiration and domain coverage without installing OpenSSL.
Works entirely in the browser with zero certificate transmission.
Tips for Best Results
- Use this tool to verify SSL certificates before deploying them to production web servers
Frequently Asked Questions
What is an X.509 certificate?
X.509 is the standard format for public key certificates used in TLS/SSL to bind public keys to domains and organizations.
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