CER File

What are CER files and how to open them

Are you having problems opening a CER file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your CER files.

What is a CER file?

CER files have multiple uses, and Internet Security Certificate is one of them. Read more about the other uses further down the page.

Internet Security Certificate

These files pertain to Internet security certificates, which are digital documents that serve as verifiable credentials for online entities.

The certificates are issued by trusted third parties known as Certificate Authorities (CA). They are used to establish the authenticity and legitimacy of websites and encrypt communication between parties to safeguard sensitive information.

Internet security certificates are an integral component of online security protocols, and the CER file format is used to store such certificates to enable their use on various computing devices.

How to open CER files

Important: Different programs may use files with the CER file extension for different purposes, so unless you are sure which format your CER file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested seven different CER openers which you will find listed below.

Last updated: January 4, 2023

All known file formats using extension .CER

While Internet Security Certificate is a popular type of CER-file, we know of 2 different uses of the .CER file extension. Different software may use files with the same extension for different types of data.

MSI/Accelrys Cerius II

We know that one CER format is MSI/Accelrys Cerius II. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Various apps that use files with this extension

These apps are known to open certain types of CER files. Remember, different programs may use CER files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about CER file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.