TE
RequestActiveTE (Transfer Encodings) tells the server which transfer encodings the client can accept in the response, and whether the client can handle trailers. Unlike Accept-Encoding (which deals with content encoding), TE deals with transfer-layer encoding. In HTTP/2 and HTTP/3, TE is a forbidden header – only 'trailers' is allowed.
TE: trailers | deflate | gzip | chunked
Description
TE indicates which Transfer-Encoding values the client understands. The 'trailers' value specifically indicates the client can process HTTP trailers – header fields sent after the chunked body. In HTTP/1.1, TE can include 'chunked', 'deflate', 'gzip'. In HTTP/2, TE is a connection-specific hop-by-hop header that is forbidden to forward – only TE: trailers is permitted and only to indicate trailer support.
Examples
Indicate trailer support
http
GET /api/stream HTTP/1.1
TE: trailers