tor circuit

a tor circuit is the chain of three relays your traffic passes through, each unwrap peeling away one layer of encryption like an onion.

a circuit is the path your traffic takes through the tor network: guard relay, middle relay, exit relay. each hop knows only its neighbors - the guard knows who you are but not your destination, the exit knows the destination but not who you are, and the middle knows neither.

the layering works like actual onion skinning. your client wraps each cell of data in three layers of encryption, and each relay peels off exactly one layer before passing it on. no single relay ever sees both the origin and the content's final destination.

circuits rotate on a schedule (roughly every ten minutes of active use), and tor deliberately uses different circuits for different destinations so your activity across sites cannot be trivially linked. onion services extend the picture: your three hops plus the service's three hops meet at a rendezvous point.

circuit behavior explains everyday tor quirks: pages occasionally loading slowly or failing and then working on retry is often just one bad relay getting swapped out of the rotation. persistent timeouts across many retries, on the other hand, usually mean the destination itself is down - which is what our status checker distinguishes.