Certificates file extensions
Digital certificate and cryptographic trust files used for identity, signing, and secure connections.
Total extensions in this category: 3
Extensions in Certificates
Explore the most searched extensions in this category.
- .cer
CER Data File
.CER is most commonly an X.509 digital certificate file used to identify a website, person, device, or organization. It typically contains a public certificate (not a private key) and can be viewed/installed with built-in tools on major desktop operating systems.
- .crl
CRL Data File
.CRL is a Certificate Revocation List file used in X.509 PKI to publish certificates that have been revoked. It’s typically opened with certificate tools (Windows Certificate Import Wizard) or inspected/converted with OpenSSL.
- .crt
CRT Data File
.CRT most commonly contains an X.509 digital certificate (often PEM or DER encoded) used for TLS/SSL and trust chains. You typically open it with certificate tools (view/import) rather than “run” it like a document.