ApplicationBinary

`application/protobuf`

Protocol Buffers

Reference for application/protobuf, the MIME type for Google Protocol Buffers binary serialization format.

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Expected extensions: .proto, .pb

HTTP Content-Type Header

HTTP Header

Content-Type: application/protobuf

Associated File Extensions

.proto.pb

Quick Facts

MIME Type	application/protobuf
Category	Application
Type	Binary
Extensions	.proto, .pb

Common Usage

Protocol Buffers (protobuf) is Google's language-neutral, platform-neutral binary serialization format. It is smaller and faster than JSON or XML.

Used extensively in gRPC services, Google's internal infrastructure, and applications that need efficient data serialization with strong schema enforcement.

Code Examples

HTML

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

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

Node.js

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

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

nginx

# nginx.conf — add to types block or use default
types {
    application/protobuf  proto pb;
}

# Or set for a specific location
location /api/ {
    default_type application/protobuf;
}