An HTTPS proxy is an HTTP proxy that supports the CONNECT method for tunneling encrypted HTTPS traffic to any destination.
Explanation
The term is mostly historical. In modern usage, every serious HTTP proxy supports CONNECT tunneling for HTTPS. The distinction mattered in the 1990s when some proxies only handled plaintext HTTP. Today, "HTTPS proxy" is often used interchangeably with "HTTP proxy" and both handle both protocols. The relevant question is not whether the proxy supports HTTPS but what it does with the connection — a plain forwarding proxy tunnels the bytes without touching them; a corporate inspection proxy with a company root cert can decrypt, inspect, and re-encrypt. Web proxies like AnyProxy handle HTTPS by connecting to the destination themselves over TLS and re-serving the response over their own TLS certificate to your browser.
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