Trailer

The Trailer response header allows the sender to include additional fields at the end of chunked messages in order to supply metadata that might be dynamically generated while the message body is sent, such as a message integrity check, digital signature, or post-processing status.

Note: The TE request header needs to be set to "trailers" to allow trailer fields.

Header type Request header, Response header, Payload header
Forbidden header name yes

Syntax

Trailer: header-names

Directives

header-names

HTTP header fields which will be present in the trailer part of chunked messages. These header fields are disallowed:

Examples

Chunked transfer encoding using a trailing header

In this example, the Expires header is used at the end of the chunked message and serves as a trailing header.

HTTP/1.1 200 OK
Content-Type: text/plain
Transfer-Encoding: chunked
Trailer: Expires

7\r\n
Mozilla\r\n
9\r\n
Developer\r\n
7\r\n
Network\r\n
0\r\n
Expires: Wed, 21 Oct 2015 07:28:00 GMT\r\n
\r\n

Specifications

Specification
Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing
# header.trailer
Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing
# chunked.trailer.part

Browser compatibility

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See also