multipart/mixed is a multipart media type.
Quick facts
What is multipart/mixed
multipart/mixed is one of the multipart media types used on the internet. When serving this content over HTTP, set the Content-Type header in the response, for example:
Content-Type: multipart/mixed
Relation chain
Related MIME types
Used with
Related headers
Related methods
Frequently asked questions
multipart/mixed is a multipart media type used to identify a content format; servers announce it to clients with the Content-Type header.
Extensions such as none registered are associated with this MIME type.
Send Content-Type: multipart/mixed in the HTTP response.
Sources & standards
Updated 2026-08-18
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