.cer X.509 certificate
Other formats
| MIME type | application/pkix-cert |
|---|---|
| Description | X.509 certificate |
| Category | Other formats |
Frequently asked questions
What is a .cer file?
A .cer file is a “X.509 certificate” (MIME type application/pkix-cert).
How do I open a .cer file?
With the program that created the file. On Linux, xdg-mime query default with the MIME type shows the default application, and xdg-open opens the file with it.
How can you tell a genuine .cer file?
No fixed signature at the start of the file is registered for this format; it is recognised mainly by its extension. On Linux and macOS, file --mime-type example.cer shows the guessed type.
Which MIME type belongs to .cer?
The MIME type is application/pkix-cert. In the Apache web server: AddType application/pkix-cert .cer; in nginx: types { application/pkix-cert cer; }.