ApplicationText-based

`application/x-pem-file`

PEM Certificate

Reference for application/x-pem-file, the MIME type for PEM-encoded certificates and keys used in TLS/SSL encryption.

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Expected extensions: .pem, .crt, .key

HTTP Content-Type Header

HTTP Header

Content-Type: application/x-pem-file; charset=utf-8

Associated File Extensions

.pem.crt.key

Quick Facts

MIME Type	application/x-pem-file
Category	Application
Type	Text-based (human-readable)
Extensions	.pem, .crt, .key

Common Usage

PEM (Privacy Enhanced Mail) is the most common format for X.509 certificates, private keys, and certificate chains. It uses Base64 encoding between BEGIN/END headers.

Used for configuring TLS in web servers (nginx, Apache), mutual TLS, code signing, and SSH key management.

Code Examples

HTML

<!-- Link or embed with explicit type -->
<link rel="stylesheet" href="file.pem" type="application/x-pem-file">

<!-- Or for script/media elements -->
<script type="application/x-pem-file" src="file.pem"></script>

Node.js

// Express.js
app.get('/file', (req, res) => {
  res.type('application/x-pem-file');
  res.send(data);
});

// Node.js http
res.writeHead(200, { 'Content-Type': 'application/x-pem-file' });

nginx

# nginx.conf — add to types block or use default
types {
    application/x-pem-file  pem crt key;
}

# Or set for a specific location
location /api/ {
    default_type application/x-pem-file;
}