HTTP headers / response header
Transfer-Encoding: chunked
Streams the body in length-prefixed chunks when the total size is unknown upfront — common for dynamically generated responses and SSE-ish streams.
Mutually exclusive with Content-Length; some old proxies (and 411-answering servers) refuse chunked requests.
The fastest way to see what Transfer-Encoding is actually doing is to send the request and read both sides raw — ReqPad shows auto-generated and custom headers for every request, on all six protocols, with history. Related references: status codes · WWW-Authenticate · Content-Encoding · ETag · Last-Modified · Expires · Location
Build the request, send it, read raw headers and timing — from your iPhone. Free to start.