BlazeMeter, locust, Loader.io, Loadrunner, Flood.io, blitz.io, Fast DDoS Attack Cmd, LoadForge, CloudTest, StresStimulus, FrugalTesting, SilkPerformer, HTTPulse, Gatling.io, LoadUIWeb, LoadStorm, AgileLoad, StormForger, Loadster, WCat, Appvance, WebLOAD, Kraken By octoPerf, UbikLoadPack, AppPerfect Load Test, LoadFocus, Load Tester, Loadium, Cavisson NetStorm are some alternatives to K6 Cloud.