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Convert CRT to CER

CRT and CER are digital certificate file formats. Both formats contain the same information, such as the certificate holder's name, the certificate's serial number, and the certificate-issuing authority's digital signature.
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convert crt to cer certificate

A CER (Certificate) file is typically issued by a certificate authority (CA) when you request a digital certificate or more commonly referred to as an SSL certificate.

it’s worth noting that CRT and CER files contain the same information, and the main difference is in the file format. So, the most important thing is to check the requirements of the system or application that you are using, and convert the file accordingly.

There are a few reasons why you might need to convert a CRT file to a CER file:

  1. File format compatibility: Some systems or applications may only accept certificate files in CER format, and not CRT format. Converting the file to CER format allows it to be used in these systems or applications.

  2. Interoperability: CER format is a standard format for X.509 certificates, which means it is more widely supported than CRT format. Converting the file to CER format ensures that it can be used in more systems and applications.

  3. File size and security: CER files are typically smaller in size than CRT files. In addition, CER files can be digitally signed and encrypted, providing an additional layer of security.

  4. Protocols compatibility: Some protocols like SCEP, require CER file format to be used as the certificate format.

Converting CRT to CER using OpenSSL

The Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols can be implemented by using OpenSSL, a free and open-source toolkit. It is widely used for the creation of digital certificates, the establishment of secure connections, and the management of public key infrastructures (PKIs).

To convert a CRT (Certificate Request File) to a CER (Certificate File), wecan use the OpenSSL tool. The command you would use is:

openssl x509 -inform PEM -in [CRT file] -outform DER -out [CER file]

This command tells OpenSSL to take the CRT file in PEM format, convert it to DER format, and save it as the specified CER file.

Converting CRT to CER using online tools

An alternative to utilising command-line programs like OpenSSL is to convert a CRT file to a CER file using an online application.

There are numerous internet resources that can help you with this step.

  1. SSL Shopper: This website offers a free online tool that can convert CRT files to CER files. Simply upload your CRT file, and the website will convert it to CER format and allow you to download the resulting file.

  2. httpcs: This website offers a free online file converter that can convert between various file formats, including CRT to CER.

It’s important to remember that using an online tool requires you to upload a file to the website, which poses a security risk. You should only use these online tools if you are confident in the legitimacy of the website and the security of the file you are uploading, it is advised. Before utilising the website’s service, you should also read the privacy statement and terms of service.

Convert .CRT file into the Microsoft .CER format

To access the certificate display, double-click the yourwebsite.crt file.
then click the Copy to file button after selecting the Details tab as shown in the screenshot


On the Certificate Wizard, click Next.
Next after selecting Base-64 encoded X.509 (.CER).

Enter the filename yourwebsite and click Browse to find the destination.
Next, choose Finished.

You now possess the document yourwebsite.cer.

Shashi kant Pandidhar

Shashi kant Pandidhar

I’ve been helping businesses to be online for over 15 years. Today my team and I, focus on helping real businesses to overcome real-life challenges and analyse data in a way that can help businesses grow in the right direction of this digital age.

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