obfs4 bridge

an obfs4 bridge is a secret tor entrance that disguises your traffic as random noise, for times when your internet provider blocks or scans for tor.

a bridge is a tor relay that is not listed in the public directory, so censors who simply block all known tor relays cannot find it by listing. obfs4 is the most widely used bridge type: it transforms tor traffic into streams of random-looking bytes with no protocol fingerprint left to detect or block.

obfs4 also authenticates its handshakes without revealing certificates or predictable patterns, and supports an iat-mode option that pads traffic to obscure packet timing - useful against censors that analyze flow shapes rather than content.

you get bridge lines from the tor browser's built-in request system (moat), from bridges.torproject.org, or from a friend who runs one. hardcoding them into config files copied from random pastebins is a habit worth dropping - stale or poisoned bridges waste your time or worse.

when to bother: if tor connects fine on your network, you do not need bridges at all - plain connections are faster. if connections hang at the bootstrap stage while normal browsing works, provider-level blocking is likely and obfs4 is the standard fix.