What SSL certificate formats can I convert between?

The SSL Converter supports conversion between PEM (.pem, .crt, .cer), DER (.der, .cer), PKCS#7 (.p7b, .p7c), and PKCS#12 (.pfx, .p12) formats. Different web servers require different formats — Apache and Nginx use PEM, Windows servers use PFX, and Java applications typically use PKCS#12.

What is the difference between PEM and DER format?

PEM is a Base64-encoded text format with header and footer lines (BEGIN CERTIFICATE / END CERTIFICATE). DER is the binary encoding of the same certificate data. PEM is human-readable and the most widely used format on Linux-based web servers.

Do I need my private key to convert a certificate format?

For converting from PKCS#12 (PFX) format, you will need the password set when the PFX was created since PFX bundles the certificate and private key together. For converting between PEM, DER, and PKCS#7 formats, only the certificate file is needed.

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SSL Converter

Convert SSL certificates between PEM, DER, P7B and PFX formats. Paste your certificate, select the conversion and download the result.

💻 OpenSSL Commands for Other Formats

PEM → DER

openssl x509 -outform der -in certificate.pem -out certificate.der

DER → PEM

openssl x509 -inform der -in certificate.der -out certificate.pem

PEM → P7B

openssl crl2pkcs7 -nocrl -certfile certificate.pem -out certificate.p7b

P7B → PEM

openssl pkcs7 -print_certs -in certificate.p7b -out certificate.pem

PEM → PFX

openssl pkcs12 -export -out certificate.pfx -inkey private.key -in certificate.pem -certfile ca-bundle.pem

PFX → PEM

openssl pkcs12 -in certificate.pfx -out certificate.pem -nodes

Frequently Asked Questions

What is the difference between PEM and DER?

PEM (Privacy Enhanced Mail) is base64-encoded and human-readable, starting with -----BEGIN CERTIFICATE-----. DER (Distinguished Encoding Rules) is the binary version of the same certificate. Most web servers use PEM format.

What is a P7B file?

P7B (PKCS#7) files contain one or more certificates but not the private key. They are commonly used on Windows servers and Java applications. The certificate is base64-encoded and starts with -----BEGIN PKCS7-----.

What is a PFX file?

PFX (PKCS#12) is a binary format that bundles the certificate, any intermediate certificates and the private key into a single password-protected file. Commonly used on Windows IIS and for importing/exporting certificates.

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