Apache JMeter, BlazeMeter, locust, Low Orbit Ion Cannon, Loader.io, OctoPerf, Loadrunner, k6 Cloud, Flood.io, Fast DDoS Attack Cmd, LoadForge, CloudTest, StresStimulus, SilkPerformer, HTTPulse, Gatling.io, YandexTank, LoadUIWeb, LoadBooster, LoadStorm, AgileLoad, StormForger, Loadster, WCat, Appvance, WebLOAD, AppPerfect Load Test, LoadFocus, Load Tester, Loadium, Cavisson NetStorm are some alternatives to Blitz.io.