How to distinguish a transparent proxy from a non-transparent one, and what are their main differences?

A transparent proxy intercepts and processes traffic without modifying requests and without requiring client configuration. The client is unaware of its existence — the proxy operates invisibly.

A non-transparent proxy requires client configuration to use the proxy server, and it is explicitly visible in network requests. The client knows that it is accessing through a proxy.

Main differences:

• Client configuration: transparent — not needed, non-transparent — needed.
• Visibility: transparent — hidden from the client, non-transparent — visible.
• Usage: transparent proxies are often used for caching or filtering without user intervention; non-transparent proxies are used for access control, authentication, and explicit traffic management.

Example: In a corporate network, there may be a transparent proxy that automatically filters websites without browser configuration, while a non-transparent proxy requires specifying its address in the browser settings.