Re:Cassowary – Modern cross-platform HTTP load-testing tool ...
by PhilippGille on Wednesday January 15, 2020 @06:42AM
(#22053409)
Another more basic (like OP's) but still popular one (>13k GitHub stars) and also written in Go is Vegeta: https://github.com/tsenart/vegeta
https://jmeter.apache.org/
https://www.radview.com/
https://www.smartmeter.io/
https://www.loadview-testing.com/
https://smartbear.com/product/ready-api/loadui/overview/