BitTorrent info

From time to time, I may link to files associated with posts which are available via BitTorrent (magnet links). Without getting overly technical, BitTorrent is a technology which allows files to be shared without the use of something like a web server; computers or devices share the files directly among each other using a “seed file” (filename ending in “.torrent”, also sometimes referred to as a “metadata file”) which contains the file names, file sizes, and enough information about the files to ensure that the correct data has been transferred (specifically, a checksum for each piece).

I recommend these BitTorrent programs (clients) specifically:

  • Unix-like and GNU variants (including the many distributions of GNU/Linux), GUI: Transmission
  • Unix-like and GNU variants, CLI/text mode: aria2
  • Multi-platform (Unix-like and GNU variants, Windows, MacOS X): Deluge
  • Android: LibreTorrent, available from the Google Play Store and F-Droid, will accept both *.torrent seed files as well as magnet links. (Older versions of LibreTorrent did not allow you to make your own torrents; this has been added in newer versions.)
  • iOS: use your computer or Android device instead (see below)

While I know of others, these are the only ones I can really feel comfortable recommending for a variety of reasons. Which one you pick depends on personal preference

Note that at the current time I specifically recommend against any unofficial Transmission binaries for Windows. I do not use Windows so cannot comment either way on the official “early preview” packages.  Also, do not use Transmission 2.90 or 2.92 for MacOS X due to malware (2.91, earlier, and later versions should be fine).

Also note if you are stuck using an iOS device (either iPhone or iPad), note that despite substantial lawful, non-copyright-infringing uses of BitTorrent technology, Apple apparently does not approve apps for the App Store that can download from BitTorrent; this could be seen as a symptom of Apple having final say on what apps are allowed in the App Store, a topic I have blogged about on many occasions. You will need to use a computer or Android device instead to download content via BitTorrent. (I am not intentionally snubbing iOS device users here by linking to torrents; Apple is, and that’s where your complaints should go.)

I also recommend against the official BitTorrent client (it is now proprietary software, specifically a rebranded version of µTorrent). The older versions of the official BitTorrent client (the ones released as free software and written in Python) are too far out of date and lack too many features to be useful in modern-day swarms (specifically, no DHT or PEX support so they must be used with a tracker; no support for magnet links).

Note that Android and other mobile BitTorrent apps may not necessarily continue downloading while running in the background. I would recommend keeping an eye on your battery level if you aren’t plugged in.

You are of course free to use something different, particularly if you have one you like. As some torrents may be shared trackerless (and trackers are known to disappear for a variety of reasons), DHT (Distributed Hash Table) should be turned on, and I recommend also enabling PEX (Peer Exchange). Both Transmission and Deluge have settings for these (I think both even have them turned on by default), and just about any other relatively modern client should as well.

Contrary to what some might tell you, use of the BitTorrent protocol and other peer-to-peer technology is not unlawful in and of itself (at least in the United States). Any BitTorrent link from this blog will be to files which I believe to be legal to download and share within, at a minimum, the United States of America. However, it is quite possible to share files via BitTorrent unlawfully (particularly with regard to copyright law) and thus by reference a potential violation of your internet provider’s terms of service/acceptable use policy. If staying squeaky-clean lawful is a concern for you, be careful about what you download using BitTorrent and make no assumptions.

Note that some particularly strict providers of internet access may not allow the use of BitTorrent at all and/or may run a non-neutral network where BitTorrent traffic is either blocked entirely, throttled/limited, logged, or otherwise interfered with. Using BitTorrent from public wireless internet access points, even if it is not specifically blocked (as it quite often is), is a bit riskier than normal and thus ill-advised; at minimum you will usually not be able to accept inbound connections (and thus, often you will not able to seed back properly), and at worst it may get your device immediately null-routed/banned from using that network. If possible, use a different port besides the “standard” port of 6881 (which is the most frequent target of blocking/limiting/throttling).