multipart/byteranges

What a server sends when one Range request asks for several slices of a file at once: each requested range arrives as its own part carrying a Content-Range header, boundary-separated like any multipart body. You meet it while debugging video seeking or resumable downloads — a single-range request gets a plain 206 with the raw slice, so this type only shows up when multiple ranges were requested. Almost nobody produces it by hand; the trap is on the client, which must parse a multipart body where it expected bare bytes.

Defined by RFC 9110 · IANA registration. Registry facts from the IANA media-types registry via mime-db.