🔐 Certificate & SSL
Free Online Certificate & SSL Tools
Decode, inspect, and convert SSL/TLS certificates, CSRs, PEM files, and cryptographic keys. All processing happens in your browser — no certificates are ever uploaded to our servers.
SSL Certificate Decoder
Decode and inspect SSL/TLS certificates
CSR Decoder
Decode Certificate Signing Requests
Certificate Decoder
Auto-detect and decode any certificate format
PEM Decoder
Decode PEM-encoded certificates, keys, and CSRs
CSR Generator
Generate Certificate Signing Requests
SSL Checker
Check SSL certificate status for any domain
Certificate Key Matcher
Verify if a certificate and private key match
Self-Signed Cert Generator
Generate self-signed SSL certificates
SSL Converter
Convert between SSL certificate formats
PFX to PEM Converter
Convert PFX/PKCS#12 files to PEM format
CER to PEM Converter
Convert CER files to PEM format
CRT to PEM Converter
Convert CRT files to PEM format
PEM to CRT Converter
Convert PEM files to CRT format
PEM to PFX Converter
Convert PEM files to PFX/PKCS#12 format
DER to PEM Converter
Convert DER-encoded files to PEM format
Frequently Asked Questions
What is an SSL/TLS certificate?
An SSL/TLS certificate is a digital credential that authenticates a website's identity and enables encrypted HTTPS connections. It binds a domain name to a public key using a trusted Certificate Authority (CA) signature.
What's the difference between PEM, DER, PFX, and CRT formats?
PEM is Base64-encoded and human-readable (used on Linux/Apache). DER is binary (used on Windows/Java). PFX/PKCS#12 bundles the certificate and private key together. CRT is just PEM with a .crt extension. Use our free converters to switch between formats.
How do I decode an SSL certificate?
Paste the PEM-encoded certificate text (between -----BEGIN CERTIFICATE----- and -----END CERTIFICATE-----) into our SSL Certificate Decoder. It extracts the subject, issuer, validity dates, SANs, public key, and fingerprints.
What is a CSR?
A Certificate Signing Request (CSR) is a block of encoded text submitted to a Certificate Authority to apply for an SSL certificate. It contains the domain name, organization details, and the server's public key.