Convert your .crt certificate into a .cer certificate file. Everything runs in your browser - your certificate never leaves your computer.
Both .crt and .cer are extensions for X.509 certificates. They can hold the exact same content - most often a Base64 PEM certificate. Windows commonly uses the .cer extension, while Linux/Unix systems favour .crt.
This tool validates your PEM certificate, normalizes the headers to -----BEGIN CERTIFICATE----- and lets you download it with the .cer extension. For a binary .cer file, use the CER to DER tool afterwards.
Convert and package keys for SSH, TLS, and keystore workflows.