What is pem File and How to Create and Open it?
By Kathir | July 30, 2026
Discover the purpose of a pem file and why it is essential. This comprehensive guide provides detailed explanations. Additionally, you will be guided on how to generate a pem file and access it on your specific operating system.
What Is a .pem File?
A Privacy Enhanced Mail (PEM) file are a popular way to store and share digital certificates, public keys, and other important cryptographic data. Since PEM files play a key role in securing digital communications, it’s helpful to understand how data encryption works before learning how they are used in SSL certificates, web servers, and email encryption.
The name PEM was initially derived from the email encryption standard, but it has since been adopted for a wider range of data formats. It is encoded in base64 and possesses a distinct structure and header that specify the nature of the contained data.
The flexibility of the PEM format allows it to store various cryptographic objects like public keys, private keys, and digital certificates, making it a popular choice for security-related applications due to its easy integration into different systems and protocols.
PEM files use Base64 encoding to represent binary data as printable ASCII characters, making it easy to transport and share cryptographic data across different platforms. They usually start with “—–BEGIN CERTIFICATE—–” and end with “—–END CERTIFICATE—–“ or similar delimiter lines, depending on the type of data they contain.
PEM files may contain a variety of certificates and RSA Keys.
1. The server certificate is a document that includes details about the public key and the corresponding identity utilized in secure web communication.
2. The private key is used to decrypt data and is part of an asymmetric key pair.
3. The Root and Intermediate Certificate: Certificate Authority certificates establish the legitimacy of additional certificates, laying the foundation for the trust framework in web security.
What Is a pem File Example?
The SSL certificates are stored in separate multiple blocks in the pem file format, following a specific chain order. Depending on the server type, you may require a PEM file containing multiple certificates such as the server and intermediate certificates, or a file containing the private key and the complete trust chain.
- The RSA Private Key — key
- The Primary Certificate — crt
- The Root Certificate – crt
Upon opening it, you would discover the following contents:
(Your Private Key: your_domain_name.key)
— –END RSA PRIVATE KEY — –
— –BEGIN CERTIFICATE — –
(Your Primary SSL certificate: your_domain_name.crt)
— –END CERTIFICATE — –
— –BEGIN CERTIFICATE — –
(Your Intermediate certificate: SectigoRSA.crt)
— –END CERTIFICATE — –
— –BEGIN CERTIFICATE — –
(Your Trust Chain Root certificate: USERTrustRSACertificationAuthorityCARoot.crt)
— –END CERTIFICATE — –
Make sure to refer to your server’s SSL installation instructions to ensure the proper file format and certificate sequence.
How to Use a .pem File for SSL Certificates?
In order to utilize a .pem file for SSL certificates, it is necessary to set up your web server with the appropriate certificate and key files. Initially, you will have to create a .pem file containing the certificates provided by your SSL provider and store them in a designated server location. Once the file is obtained, it can be utilized in both Nginx and Apache web servers.
For Nginx, the path to the .pem file must be specified in the server configuration. As for Apache, the SSLCertificateFile and SSLCertificateKeyFile directives need to be specified in the virtual host configuration.
Utilizing the .pem text file guarantees that your web server possesses the essential SSL certificates required to activate secure HTTPS encryption for your domain.
How to Create a .pem File?
You have the option to manually create the file or use an external tool such as OpenSSL. If you have purchased an SSL certificate from a CA, you can access the required SSL files and then transfer the contents to another file with the PEM file extension by copying and pasting. It is important to maintain the correct certificate order according to the guidelines provided by your provider. Refer back to our PEM example to ensure the proper certificate sequence.
How to Generate a .pem File From a Private Key?
- First, open a terminal or command line.
- Go to the folder where your private key is located.
- Execute the following command:
openssl rsa -in private.key -outform PEM -out private.pem
How to Convert a .pem File?
You have the option to transform a .pem file using OpenSSL or an external file conversion tool. Common conversions involve changing from PEM to PFX or CRT extensions.
How to Create a .pem File from .crt
To generate a .pem certificate file from a .crt file, you will need to go through a conversion process. However, since a .crt file is already in the PEM format, there is no need for any extra steps to convert it. Simply renaming the file extension will create the .pem file from the .crt file
Related Useful Resources:
1. Simple Steps to Install SSL certificate on Windows Server
2. Install SSL certificate on Windows Server
Conclusion
In summary, PEM is among the many file formats used to store cryptographic keys and digital certificates. Utilizing OpenSSL or similar conversion tools makes it easy to manage certificate files and work with different extensions.
Whether you are a developer, IT professional, or just interested in the topic, mastering the use of .pem files can improve security across different applications and protocols.