// mime type · application type
application/octet-stream
Arbitrary binary data (download) · .bin
What application/octet-stream is
application/octet-stream means arbitrary binary data of unknown type — the generic 'just download it' type. Browsers won't try to render it, so it reliably triggers a save dialog.
How it's used
You'll see this as a Content-Type value on requests and responses — for example Content-Type: application/octet-stream. It's the type associated with the .bin file extension. Application types cover structured data and binary formats — from JSON and XML to PDFs, archives, and Office documents.
Other application types
application/json application/ld+json application/xml application/javascript application/pdf application/zip application/gzip application/octet-stream application/x-www-form-urlencoded application/wasm application/vnd.openxmlformats-officedocument.spreadsheetml.sheet application/vnd.openxmlformats-officedocument.wordprocessingml.document