If you should happen to try out k6 in the meantime, most of the JSON contents should be recognizable/understandable just by looking at the output, if you know what metrics k6 collects (which is documented on docs.k6.io). You can try running with e.g. 2 VUs for 2 iterations, to get a tiny amount of output data but something that looks like a real load test: k6 run --vus 2 --iterations 2 --output json=output.json script.js