Measures response times, usually in milliseconds.
Proxy-Seller Online Tool : Allows you to check up to 100 proxies at a time for free, providing detailed reports on location and speed. Download Proxy Checker SLAYER zip
Detects if the proxy is transparent, anonymous, or elite (hides your real IP and the fact that a proxy is being used). Measures response times, usually in milliseconds
ProxyScrape Online Checker : A free tool where you can paste your list directly into the browser. It supports multi-protocol checking without any downloads. Measures response times
Verifies if the proxy works with HTTP, HTTPS, SOCKS4, or SOCKS5. Safer Alternatives to SLAYER
A professional-grade tool included with the Proxifier software suite, known for its reliability and detailed diagnostic reports. monosans/proxy-scraper-checker - GitHub