19.2 Internet Media Type multipart/byteranges

When an HTTP 206 (Partial Content) response message includes the content of multiple ranges (a response to a request for multiple non-overlapping ranges), these are transmitted as a multipart message-body. The media type for this purpose is called "multipart/byteranges".

The multipart/byteranges media type includes two or more parts, each with its own Content-Type and Content-Range fields. The required boundary parameter specifies the boundary string used to separate each body-part.

Media Type name:


Media subtype name:


Required parameters:


Optional parameters:


Encoding considerations:

only "7bit", "8bit", or "binary" are permitted

Security considerations:


For example:

HTTP/1.1 206 Partial Content

Date: Wed, 15 Nov 1995 06:25:24 GMT

Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT

Content-type: multipart/byteranges; boundary=THIS_STRING_SEPARATES


Content-type: application/pdf

Content-range: bytes 500-999/8000

...the first range...


Content-type: application/pdf

Content-range: bytes 7000-7999/8000

...the second range



  1. Additional CRLFs may precede the first boundary string in the entity.

  2. Although RFC 2046 [40] permits the boundary string to be quoted, some existing implementations handle a quoted boundary string incorrectly.

  3. A number of browsers and servers were coded to an early draft of the byteranges specification to use a media type of multipart/x-byteranges, which is almost, but not quite compatible with the version documented in HTTP/1.1.