Honestly, I still don’t get how to check or know in advance that a proxy is reliable and will work steadily. From time to time I need a good proxy to look like a user from another country https://nerdbot.com/2025/04/14/germany-proxy-and-usa-proxy-sometimes-you-just-gotta-look-local/. The only thing I usually rely on is proxies from a reliable provider with an already solid reputation. Other than that, I have to test everything myself from experience.