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application/cbor

application
.cbor
IANA registration →

The MIME type for CBOR (Concise Binary Object Representation) data, defined by RFC 8949. Used in FIDO2/WebAuthn authenticator responses, IoT payloads, and CoAP. application/cbor is the standard type; application/cose for CBOR Object Signing and Encryption (COSE, RFC 8152).

Details

application/cbor is registered by RFC 8949 for CBOR binary encoding.

Where you encounter application/cbor: - FIDO2/WebAuthn: authenticatorData, attestationObject in credential responses - CoAP (Constrained Application Protocol): IoT messaging - COSE (RFC 8152): signed and encrypted CBOR objects - Cloudflare/Apple OHTTP internal responses

When to use application/cbor: - Binary efficiency is needed over JSON - FIDO2/WebAuthn spec requires it - CoAP-based IoT systems - Compliance with specs that mandate CBOR (WebAuthn, COSE)

Common use

FIDO2/WebAuthn credential responses, CoAP IoT payloads, COSE objects

See Also

All MIME TypesMIME Types OverviewIANA Media Types Registry