Security & certificates

SSL certificate converter

Paste a certificate or open a file: get PEM, DER or a P7B bundle, and see who issued it and when it expires.

Runs entirely in your browser — nothing you enter is sent to our servers.

Certificate(s) in PEM

Open file (.pem, .crt, .cer, .der, .p7b)

How it works

PEM is Base64 text between BEGIN/END lines — what nginx, Apache and most Linux software expect. DER is the same certificate in binary, common on Windows and Java. P7B bundles several certificates (usually the full chain) without a key. Converting a chain? Paste all certificates at once and download the P7B. PFX needs your private key and a password, so we leave that to openssl on your own machine.

FAQ

Do you need my private key?

No. Certificates are public, and this converter works only with them. For PFX/P12 the key is required, and the command below lets you build it locally.

My file won't open — why?

Check that it's a certificate and not a CSR or a key. PEM files must contain -----BEGIN CERTIFICATE----- or -----BEGIN PKCS7-----.