Transmission
FreeA quiet, lightweight client you can leave running for years
An open-source BitTorrent client known for staying out of the way — minimal interface, minimal footprint. It can run as a headless daemon with a web interface, which makes it the most common download backend on NAS boxes, Raspberry Pis and home servers.
Why we picked it
If qBittorrent is the full-featured desktop client, Transmission takes the opposite road: as little interface as possible, as little presence as possible. On macOS it is a native Cocoa app that looks like it shipped with the system; on Linux it is the default BitTorrent client in most major distributions.
Unattended operation is where it really belongs. transmission-daemon runs with no GUI at all,
and you add jobs from a browser or a phone app. An old laptop, a Raspberry Pi or a Synology box
plugged in and forgotten in a corner for years — for that job it fits better than a client
carrying a full desktop interface.
The trade-off is a genuinely smaller feature set. There is no built-in search like qBittorrent's, RSS auto-download needs third-party scripts or plugins, and there are fewer advanced knobs. That is a design choice, not a shortcoming.
How to choose: for occasional downloads on a desktop where you want a capable window, take qBittorrent. For a download backend on an always-on machine where every megabyte of RAM counts, take Transmission.