Convert a .cer certificate - PEM text or binary DER - into a .crt certificate file. Everything runs in your browser.
Both .cer and .crt are X.509 certificate extensions. A .cer file may be Base64 PEM or binary DER. This tool detects the format automatically and outputs a Base64 PEM certificate that you can save as .crt.
Paste PEM text and click Convert, or load any .cer file - binary DER files are decoded to PEM instantly, the browser equivalent of openssl x509 -inform DER -in cert.cer -out cert.crt.
Convert and package keys for SSH, TLS, and keystore workflows.