SSL Certificate Decoder - Analyze X.509 Certificates
Decode and analyze SSL/TLS X.509 certificates online. View certificate details including issuer, subject, validity period, public key, and extensions.
Educational Tool
This is a simplified educational tool. For production certificate analysis, use OpenSSL or online tools like SSL Labs.
SSL Certificate Decoder
Certificate Best Practices
- • Use certificates from trusted Certificate Authorities
- • Enable HTTPS for all web traffic
- • Renew certificates before expiration
- • Use 2048-bit or higher RSA keys
- • Implement Certificate Transparency monitoring
What is an SSL/TLS Certificate?
SSL/TLS certificates are digital certificates that authenticate a website's identity and enable encrypted connections. They contain information about the certificate holder, the certificate authority that issued it, and the public key used for encryption.
Certificate Components
Subject
Information about the certificate holder (domain name, organization, location)
Issuer
The Certificate Authority (CA) that issued and signed the certificate
Validity Period
Start and end dates for when the certificate is valid
Public Key
The public key used for encryption and signature verification
Certificate Types
- Domain Validated (DV): Basic validation, verifies domain ownership
- Organization Validated (OV): Verifies organization identity
- Extended Validation (EV): Highest level of validation and trust
- Wildcard: Covers all subdomains of a domain
- Multi-Domain (SAN): Covers multiple different domains
Certificate Management Tools
OpenSSL
Command-line tool for certificate generation and analysis
Let's Encrypt
Free, automated certificate authority
SSL Labs
Online SSL/TLS testing and analysis
Certbot
Automated Let's Encrypt certificate management