SSL Format Converter

Convert certificates between PEM, DER, PFX, and P7B formats. Drag and drop files or paste content directly.

Source Format (Convert From)

Destination Format (Convert To)

Certificate PEM (CRT / CER) *

Private Key PEM *

Password / Passphrase

Windows Server PFX Compatibility

Modern Windows (AES256-SHA256 - Server 2016+ / Win 10+)

Legacy Windows (TripleDES-SHA1 - Server 2008/2012)

Certificate Format Glossary

SSL/TLS certificates are distributed in several formats. Here is a brief explanation of each:

PEM

PEM (Privacy Enhanced Mail)

ASCII text format starting with '-----BEGIN CERTIFICATE-----'. Used widely by Nginx, Apache. Can contain leaf cert, intermediates, and private keys.

PFX

PFX / PKCS#12

A binary archive containing both certificates and the private key, secured by a password. Primarily used by Microsoft IIS (Windows).

DER

DER (Distinguished Encoding Rules)

Raw binary form of a certificate or key. Typically used in Java environments (Tomcat, WebLogic) or security hardware modules (HSM).

P7B

P7B / PKCS#7

ASCII format (wrapped in '-----BEGIN PKCS7-----') containing only certificates and chains, without the private key. Used by Windows IIS and Tomcat.

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