DER file format description

DER file format

We made this page to help you understand how to work with DER files. Here, you can find info on software that can handle these files. It includes simple programs for opening and converting them.

Learn about the DER file and its functions here!

We also explain how to convert them into other types. It's simple and hassle-free. For opening or changing DER files, this page offers all the tools you need.

#1 Certificate File

The DER file is categorized under Data. It is associated with OpenSSL, serving as a Certificate File. The Distinguished Encoding Rules file contains a binary representation of a certificate, including its public key, but not its private key. Visit the website of OpenSSL for a detailed description of the DER format.

Category:Data files
Magic:- / -

Certificate File related extensions

  • ca OpenSSL Certificate Authority Data
  • cerf Certificate Enrollment Request File
  • crt Certificate File
  • csr Certificate Signing Request Data

Did someone accidentally misspell the DER filename?

The DER filename extension may be misspelled. We compiled a list of similar file extensions to help you find errors.

Filename extensions similar to DER:

Windows can't open your DER file?

When you try to open a file by double-clicking it, Windows looks at the file's name to figure out what to do. If Windows doesn't know the file type, it'll ask you to choose an app to open this DER file.

To set the DER file association in Windows 11, you can follow these steps

  1. Open the Settings app by clicking on the Start menu and selecting the gear icon.
  2. In the Settings app, click on System and then select Apps from the left-hand side menu.
  3. Scroll down and click on the Default apps option.
  4. In the Default apps section, you will find various categories. They include Email, Web browser, and Music player.
  5. Locate the category that matches the file type you want to associate. For example, choose Photos for image files, or Video player for video files.
  6. Click on the current default app listed under the category. A list of available apps will appear.
  7. Choose the app you want to set as the default for that file type. If the app you want is not listed, click on More apps to see more options. Or, click on Look for an app in the Microsoft Store to search for apps.
  8. After selecting the app, it will become the default choice for opening files of that type.

It's worth mentioning that you don't always need to set DER file association. Many apps can open files. They don't need a specific file association to be set.

Handle DER files with care

Exercise caution when handling DER files from unknown sources. Files from certain sources can threaten your computer's security. They might contain malware, viruses, or harmful software. To minimize risks, avoid downloading or opening unfamiliar DER files. Use trusted antivirus software to scan files from unknown sources before opening.

If you find the information on this DER page useful, please feel free to link to this page. >> DER file