---
title: "📋 OpenSSL: Converting certificate formats (.cer, .crt, .pem) to .pfx"
url: "https://support.ftapi.com/en/article/openssl-zertifikatsformate-cer-crt-pem-in-pfx-konvertieren"
language: "en"
last_updated: "2026-06-22T07:11:25.283Z"
---

# 📋 OpenSSL: Converting certificate formats (.cer, .crt, .pem) to .pfx

This article shows administrators how to use the command-line tool OpenSSL to convert various SSL certificate formats into the required .pfx file and how to include intermediate certificates.

## 📋 OpenSSL: Converting certificate formats (.cer, .crt, .pem) to .pfx

If your SSL certificate is in a format such as `.cer`, `.crt`, or `.pem` and you possess the corresponding private key (usually a `.key` file), you can use OpenSSL to convert these into the required `.pfx` format.

OpenSSL is a command-line tool available on many servers.

## Converting the certificate

Use the following command in the command line (terminal or command prompt):

```plaintext
openssl pkcs12 -export -out YourCertificate.pfx -inkey YourPrivateKey.key -in YourCertificate.cer
```

### Replacing placeholders

Replace the placeholders in the command above with your actual file names:

-   `YourCertificate.pfx`: The desired name for the new `.pfx` file.
-   `YourPrivateKey.key`: The file name of your private key.
-   `YourCertificate.cer`: The file name of your certificate (can also be a `.crt` or `.pem` file).

## Including intermediate certificates

If you also need to include intermediate certificates (these are often provided by the CA as a separate file, e.g., `IntermediateCertificates.pem`), extend the command as follows:

```plaintext
openssl pkcs12 -export -out YourCertificate.pfx -inkey YourPrivateKey.key -in YourCertificate.cer -certfile IntermediateCertificates.pem
```

Additionally, replace `IntermediateCertificates.pem` with the file name of the file containing your intermediate certificates.

### Setting an export password

During the process, you will be prompted to set an export password for the `.pfx` file. This password will be required for later installation.

> **Important: The assigned password must be communicated to FTAPI Support along with the .pfx file via a secure channel (e.g., SubmitBox).**

## **Related articles**

> #### [**❓ What to do in case of "Insecure connection" / expired SSL certificate?**](https://support.ftapi.com/de/article/-was-tun-bei-unsichere-verbindung-abgelaufenem-ssl-zertifikat)
> 
> #### [**📋 Windows: Create .p12 / .pfx certificate from a .p7b file**](https://support.ftapi.com/de/article/windows-p12-pfx-zertifikat-aus-einer-p7b-datei-erstellen)