How can I test if a proxy works?

If you want to make sure that your proxies are working fine, you can do so in your computer's terminal with a command-line tool cURL. Type the one you need into your domain:port field:

curl -U user:pass -x domain:port https://www.whatismyip.com/

For example, to test a proxy with any location and a fast rotating session:

curl -U username:password -x any.metrow.com:8000 https://www.whatismyip.com/