dl/third/libcurl/docs/cmdline-opts/limit-rate.md

c, SPDX-License-Identifier, Long, Arg, Help, Category, Added, Multi, See-also, Example

c	SPDX-License-Identifier	Long	Arg	Help	Category	Added	Multi	See-also	Example
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.	curl	limit-rate	<speed>	Limit transfer speed to RATE	connection	7.10	single	rate speed-limit speed-time	--limit-rate 123.45K $URL --limit-rate 1000 $URL --limit-rate 10M $URL --limit-rate 200K --max-time 60 $URL

--limit-rate

Specify the maximum transfer rate you want curl to use - for both downloads and uploads. This feature is useful if you have a limited pipe and you would like your transfer not to use your entire bandwidth. To make it slower than it otherwise would be.

The given speed is measured in bytes/second, unless a suffix is appended. Appending 'k' or 'K' counts the number as kilobytes, 'm' or 'M' makes it megabytes etc. The supported suffixes (k, M, G, T, P) are 1024-based. For example 1k is 1024. Examples: 200K, 3m and 1G.

The rate limiting logic works on averaging the transfer speed to no more than the set threshold over a period of multiple seconds.

If you also use the --speed-limit option, that option takes precedence and might cripple the rate-limiting slightly, to help keep the speed-limit logic working.

Starting in curl 8.19.0, the rate can be specified using a fraction as in 2.5M for two and a half megabytes per second. It only works with a period (.) delimiter, independent of what your locale might prefer.