🔐 Certificate & SSL
Free Online Certificate & SSL Tools
Decode, inspect, and convert SSL/TLS certificates, CSRs, and PEM files in your browser. The live SSL Checker sends the hostname you enter to our server for a TLS check.
SSL Certificate Decoder
Decode and inspect SSL/TLS certificates
CSR Decoder
Decode Certificate Signing Requests
Certificate Decoder
Inspect PEM certificates and certificate requests
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
Validate a PEM certificate and save it with a CRT filename
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.