Transmission has been built from the ground up to be a powerful yet lightweight BitTorrent client. Its simple and intuitive interface is designed to integrate seamlessly with whatever computing environment you choose to use.
Streaming strikes a balance between providing useful functionality without feature overload. Plus, it's free for anyone to use or modify.
Characteristics
- Uses fewer resources than other clients
- Native Mac GUI clients, GTK+ and Qt
- Ideal daemon for servers, embedded systems and headless use
- All of these can be remotely controlled by Web and Terminal clients.
- Discovery of Local Pairs
- Full encryption, DHT, ยตTP, PEX and Magnet Link support
Streaming runs natively on more than five operating systems. Perfectly configuring your network, intelligently banning peers that send corrupted data, and built-in Peer-to-Peer Sharing are some of the features that allow Transmission to download your files as quickly as possible. All of this is done in the background, without the user having to worry about complicated settings.
Bandwidth is a precious commodity these days. Transmission allows you to ration this product efficiently. You may want to queue your torrents for maximum performance. Or slow down during peak periods.
The transmission allows you to easily do both and therefore only works at its best when you want it to. Support for Growl notifications and port badges keep you up to date with what's going on so you can get back to doing more important things.
NOTE: The stream is completely open source, with most code under the MIT Liberal License and select code under the GNU General Public License.
What's new
This is a major release, both in numbers and effort! It has been in active development for over a year and has a huge changelog, over a thousand commits, since Transmission 3.00. Some of the highlights include:
- Resource Efficiency - Use less memory and fewer CPU cycles
- Better Community: Pull Requests are Welcomed and Used
- Code modernization: migrated from C90 to modern C++
- New features โ what would a major release be without them?
resource efficiency
- The code has been extensively profiled and improved to fix inefficient code and memory usage. For example, a stress test of starting the transmission daemon with 25,000 torrents is almost completely tied to IO, using 50% fewer CPU cycles and 70% fewer memory allocations than Transmission 3.00.
- The remote control GUIs (transmission-qt and Transmission-web) now use the RPC API "table" mode, resulting in smaller payloads / less bandwidth usage.
- RPC payloads are now compressed using libdeflate, a "highly optimized [library that is] significantly faster than the zlib library.โ
Community
- The project is much more responsive to bug reports and code submissions than in the past.
- There's a new group of volunteer supporters working on Transmission!
- Transmission 4.0.0 includes over 350 new community engagements (see Thank You section below and in previous 4.0.0 betas) since 3.00 and welcomes new contributors.
- Documentation has been moved to streaming/streaming so contributors can submit PRs to improve it.
Code modernization
- All code base has been migrated from C to C++. In the process, we remove thousands of lines of custom code and use standard C++ tools instead. The core code has been reduced by 18%. The core codebase has been extensively refactored to make it more testable and maintainable.
- The GTK client has been ported to gtkmm.
- The web client has been rewritten in modern JavaScript and no longer uses jQuery. The entire gzipped package is now 68K in size.
- Unit tests have been expanded and moved to Google Test. Clang Sanitizer builds run during CI.
- The core library is now fuzz tested.
- Streaming now uses Sonarcloud, Coverity, LGTM, and clean and neat static analysis in the new code. Fixed several hundred code warnings compared to Transmission 3.00.
new features
- Support for BitTorrent v2 torrenting and hybrid torrenting. (Support for v2 and hybrid torrenting is scheduled for a future release.)
- Users can now set "default" trackers that can be used to advertise all public torrents.
- Newly added seeds can start immediately and check parts on demand, rather than needing full verification before seeding can begin. (#2626)
- Added an option to omit potential identifying information (eg user agent and creation date) when creating new torrents. (#3452)
- The web client has been rewritten and is now compatible with mobile use.
- When creating new torrents, users can now specify the size of the piece. (#3768, #3145, #2805)
- IPv6 blocklists are now supported. (#3835)
- As of 4.0.0-beta.1, Transmission builds now use semver builds.
- Dozens of other new features - too many to list here! We've been working on this for a year!
What's new since 4.0.0-beta.3
libtransmission (all platforms)
- Added a new setting, torrent-added-verify-mode, to force verification of added torrents. (#4611)
- Improved handling of webseed servers not supporting range requests or partial content 206. (#4601)
- Improved handling of webseed servers returning a content encoding that was not requested. (#4609)
- Fixed possible socket leak 4.0.0-beta.3. (#4616)
- Fixed regression 4.0.0-beta.3 not detecting large file compilation flags on 32-bit systems. (#4627)
- Fixed 4.0.0-beta.1 UI error when removing a tracker from the ad list. (#4635)
- Improved error handling when receiving corrupted part data from teammates. (#4665)
- Fixed 4.0.0-beta.1 FTBFS bug on CentOS 7. (#4673, #4675)
- Made minor performance improvements to libtransmission. (#4577, #4679)
- Removed the libiconv dependency on libtransmission. (#4565)
- Error message 403 RPC updated. (#4567)
- Improved libdeflate snapshot to 1.17. (#4596)
macOS client
- Fixed two Help menus on macOS. (#4500)
- Fixed a bug that caused magnet links to always stop when added. (#4528)
- Fixed regression 4.0.0-beta.1 breaking the part view "flickering" when a part is completed. (#4587)
- Made sure the preferences window is centered the first time it is displayed. (#4659)
- Fixed regression 4.0.0-beta.1 incorrectly handling corrupted blocklists. (#4705)
- Increased the font size in the main window torrent list. (#4557)
- Fixed libpsl dependency compilation issue on macOS. (#4642)
client qt
- Made the display order of speed limits consistent between the Properties and Details dialogs. (#4677)
GTK client
- Fixed 4.0.0-beta.1 regression making it impossible to close the "Set Location" dialog (GTK 3 only). (#4625)
- Fixed regression 4.0.0-beta.2 causing a crash while rendering progress bars on some systems. (#4688)
web client
- Fixed 4.0.0-beta.1 potential crash when detecting MIME types. (#4569)
- Fixed 4.0.0-beta.1 regression breaking file priority buttons in web client. (#4610)
Devil
- Fixed stderr logging issue when running as a systemd unit. (#4612)
remote transmission
- Fixed 4.0.0-beta.1 regression when displaying session information. (#4624)
- Fixed 4.0.0-beta.1 regression displaying tracker info. (#4633)
