Media Type Registry

Binary: Non-text-based media types

Media Type(s):

• application/octet-stream (IANA) – RFC2045, RFC2046 §4.5.1
• audio/* (IANA) – RFC2045, RFC2046 §4.2
• image/* (IANA) – RFC2045, RFC2046 §4.2
• video/* (IANA) – RFC2045, RFC2046 §4.4

This page also applies to any unrecognized binary media type.

OAS References:

• Working with Binary Data (Schema Object)
• Binary Streams (Media Type Object)
• Content-Transfer-Encoding and contentEncoding (Encoding Object)

Summary

As of OAS v3.1, binary data is modeled using an empty Schema Object, in accordance with JSON Schema’s guidance regarding non-JSON instances.

Remarks

As specified in Working with Binary Data, modeling binary data that has been encoded into a string is handled differently from raw binary data, with two variations: with the Schema Object’s contentMediaType and contentEncoding, or with a Content-Transfer-Encoding header in the Encoding Object (for media types that use Encoding Objects). Consult the specification for how these two mechanisms interact when they both apply.

In OAS v3.0, raw binary content was modeled as type: string, format: binary, while type: string, format: byte was used for base64-encoded binary. This was dropped in favor of JSON Schema draft 2020-12’s support because it did not allow specifying the media type along with the binary encoding.