I remember I have used a Windows proxy testing software a long time ago. The software allows me to input say 100 proxy at a time, and I could set a destination url (for example, Google.com or Facebook.com/messages/) and then test how many proxies in the list can visit the destination url (and at what speed). I am wondering if there is a similar application on OSX can do the similar thing. Thanks!
And it runs on linux, windows, android, or even iOS. It's a npm tool called proxy-checker (https://www.npmjs.com/package/proxy-checker). Enjoy.