FastSpeedTest works the same way for everyone, everywhere, the test transfers data between your browser and Cloudflare's global edge network, which has points of presence in 300+ cities. The numbers you see reflect your real connection. What changes is which provider you have, and how that provider behaves in your country. This guide is a neutral, side-by-side look at the major residential ISPs in the regions our users come from most.
Open your provider's guide to see realistic speed ranges and the most common reasons real-world tests come in below the advertised plan. Then run a wired test, compare against the numbers in the guide, and you'll know whether the issue is your ISP or something inside your home network.