The best alternatives to Down Speed are speed-test-cli, Web Load Speed Test, and LiveChat. If these 3 options don't work for you, we've listed a few more alternatives below.
What do you think of Down Speed?
Postman Recorder by DevTools— Export Postman APIs from browser
Speediness lets you quickly check your internet connection speed and latency. Tests are run in parallel to better reflect real-world situations. The app requires macOS 12 or later.
ISP Logger is an automated internet speed performance analytics tool. A small open source script performs a speed test on a docker image every hour and can be analysed on the easy to use Dashboard.