curl-w32/docs/cmdline-opts/no-buffer.md

c	SPDX-License-Identifier	Long	Short	Help	Category	Added	Multi	See-also	Example
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.	curl	no-buffer	N	Disable buffering of the output stream	curl	6.5	boolean	progress-bar	--no-buffer $URL

--no-buffer

Disables the buffering of the output stream. In normal work situations, curl uses a standard buffered output stream that has the effect that it outputs the data in chunks, not necessarily exactly when the data arrives. Using this option disables that buffering.

Note that this is the negated option name documented. You can use --buffer to enable buffering again.