Proxifier - Proxy Checker Proxy Checker tool is integrated into Proxifier, but it can be useful on its own. It allows you to test proxy servers and check whether they can work
How to Check Proxies with Proxy Checkers | Best Proxy Reviews
Free Proxy Scanner - How to Bulk Scan and Test Proxies | Best Proxy Scanning Tools
proxy-checker-cli - npm
Proxy Server: Proxy software
GitHub - assnctr/unfx-proxy-checker: Unfx Proxy Checker - Powerful proxy checker with huge features and beautiful design. Easy sorting and filtering by all parameters.
Free Web Proxy Checker 1.5.19 download - FreewareLinker.com