File Extension CER

  • Full name
    Internet Security Certificate
  • Developer
  • Popularity
Have you encountered a problem with a CER file? Don’t you know which program opens a file with this extension? You will find all the information you need about working with a CER file here. In the further part of this page we have added a list of programs that should open your CER file. It is enough you choose a proper application for your operating system, download and install it.

What is CER file?

The most common application is the Internet Security Certificate. These files are provided by various providers, also called certificate authority, such as Thwate or VeriSign. These will then be installed on the web server to ensure the validity of the website being accessed.

More info

Mostly used in conjunction with an encrypted, secure HTTPS connection, the CER files can be viewed in any browser. Depending on the browser, a simple or double-click on the lock symbol is sufficient.

Programs which can open a CER file

How to open file with CER extension?

In order to open a file with CER extension one of the following programs must be installed on user’s system. If a problem with opening CER file occurred, it is highly possible that none of the listed programs is present on user’s system. Even if one or more said programs are installed, there may be issues related with given programs. In order to solve a problem with CER files, follow the instructions below.
Install Safari or other program from the list

Most often resolving problems with opening CER files is very simple. Just install an appropriate program that supports such files. All of the listed programs support CER files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of CER files or offer file conversion options, but may not be capable of editing such files.

Set Safari as the default program for opening CER files

It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate CER files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Safari applications is not on the list, select "Browse" option in order to manually locate the directory where Safari has been installed.


Check the section that lists most common problems with CER files

Sometimes problems with opening CER files may not lie with the application itself, but can arise due to other causes, such as:

  • File data is corrupted
  • CER files has been not been completely download from the internet (only a part of the data has been downloaded)
  • Currently used user account hasn’t been granted necessary privileges to open CER files (should that be the case, please contact your system administrator or IT specialist)
  • CER file was being copied from a corrupted storage device and is incomplete or data is corrupted. (Copying files from unknown or untrusted sources should be conducted with great care as such files may contain malicious software, which can damage your system)

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