check proxy with target - SERP Analysis

https://infatica.io/proxy-checker/

https://pingproxies.com/proxy-tester

https://www.reddit.com/r/webscraping/comments/1guzeki/target_website_detecting_that_proxies_are/

https://stackoverflow.com/questions/51096547/how-to-get-the-target-of-a-javascript-proxy

https://proxyscrape.com/online-proxy-checker

https://checker.proxyempire.io/

https://iproyal.com/online-proxy-checker/

https://docs.cloud.google.com/load-balancing/docs/target-proxies

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy

https://proxyway.com/tools/free-online-proxy-checker