certificate file extensions

There’s no doubt that the world of SSL certificates can be highly confusing for someone who is new to the industry. One of the reasons behind this is the different formats in which SSL certificates are issued. Yes, you read that right: SSL certificates can be issued in various formats such as CER, CRT, DER, PEM, P7B, P7S, PFX, P12, etc. That’s because SSL certificates are issued with different certificate file extensions or in different file formats — such as a PKCS7 certificate or a DER certificate — based on their encoding and the information they store.

CER, CRT, DER, PEM, P7B, P7S, PFX, and P12. Do you feel like pulling your hair when you see so many SSL/TLS certificate formats and extensions? Well, you’re not the only one. In our experience, a person dealing with SSL certificates passes through this stage at least once in their life. So, don’t worry as many have been there (and many are yet to arrive). In the meantime, we want to help by making this phase as short as possible for you. And that’s why we’ve come up with this article — to help you clear up any confusion regarding CER vs CRT files.