When comparing BitTorrent Surf vs Deluge, the Slant community recommends Deluge for most people. In the question“What are the best Torrent clients?” Deluge is ranked 3rd while BitTorrent Surf is ranked 21st. The most important reason people chose Deluge is:
Deluge is free, ad-less and open source software licensed under GPL with source code available [here](http://dev.deluge-torrent.org/wiki/GitRepo). Being open source allows anyone to check if the software has no malicious code, is secure and respects privacy.
Ranked in these QuestionsQuestion Ranking
Pro Built-in custom search
Built-in search engines allow finding torrents to download right from withing the torrent client. BitTorrent Surf can be customized to include multiple custom search engines.
Pro Free, ad-less and open source
Deluge is free, ad-less and open source software licensed under GPL with source code available here. Being open source allows anyone to check if the software has no malicious code, is secure and respects privacy.
Deluge covers basics such as Prioritization, Selective Downloading, DHT, PEX, LPD and Magnet URIs. It includes MSE/PE for security. It has graphical, web and command line interfaces. Has UPnP, NAT-PMP, NAT traversal for automatic router configuration. Has UDP tracker data transfer protocol support. Even covers IPv6 and proxy servers.
Pro Good web UI
Deluge has a web interfaces that can be used to remotely control torrents.
Deluge weighs under 15MB.
Pro Functionality can be extended with a variety of plugins
As is, Deluge is very stripped down, but its functionality can be increased via plugins. As such Deluge can have only the functionality that is needed and skip any other reducing resource usage.
Pro Has a command line interface and a daemon
Deluge can be run in text-only mode via the
deluge-console command. Requires first running the deluge daemon
deluged. Utilizing the deluge daemon
deluged allows remotely connecting to it, and using any front-end interface.
µTorrent can be run without having to be installed. It can be put on an external storage device (such as a USB drive) and run directly from it. A portable version of Deluge can be downloaded from SourceForge.
Pro Can encrypt traffic
MSE/PE or Message Stream Encryption/Protocol Encryption is BitTorrent traffic encryption method designed to improve privacy. It also attempts to make it harder to identify BitTorrent traffic by third parties such as ISPs that can choose to throttle it.
Pro Utorrent compatible
You can download using both clients µTorrent and Deluge on any supported operating system.
Con Slow development
BitTorrent Surf has been in beta since it was announced in 2013. No changes to the add-on have been made since.
Includes "BitTorrent Bundle recommendations".
Con Unknown underlying technology
It is unclear what BitTorrent protocol features or extensions are supported by the add-on.
Con Includes minor UI issues
Deluge has minor UI issues such as presenting "delete with data" as the most prominent button when removing a torrent from a list of downloads, or the way it resets its size when maximized from tray forcing a resize each time.
Con Can't "force start" downloads
There's no way to manually override settings for download queuing that's available in other torrent clients. For example, if there are 2 files in the download list and the software is configured to queue just one at a time there's no way to force a download of both without changing the settings. A workaround plugin can be found here.
Con Does not preload magnet data
If a magnet URI is used there's no way to get information about contents or perform any kind of actions (such as selecting what to download) before the download has started.
Con Files can't be downloaded sequentially by default
Sequential downloading can be used to stream media files such as video and audio while the download is still in progress. By default, Deluge requires waiting until the complete file is downloaded before it's ready for use.
But it should be mentioned that there exists a plugin: https://github.com/JohnDoee/deluge-streaming for video streaming from Deluge.
Con No built-in search engine
Built-in search engines allow finding torrents to download right from withing the torrent client. Deluge lacks such functionality.
Con No web seeding suport
Web seeding support allows downloading file parts from an HTTP source alongside the swarm. It's usually used for long-term seeding and easing some of the load on web hosts that supply direct downloads by offering a BitTorrent download as an alternative while still ensuring that the file is always available in its entirety regardless of the swarm. Deluge lacks this functionality.
Con Demon not lightweight as expected
While it has been improved a lot in the last years, when it's used in "headless" mode, the python demon still tends to use more resources than expected. It's noticeable especially on devices like the raspberry, and for instance, rtorrent and transmission use much less CPU.
Con No tracker exchange
Tracker exchange functionality allows peers to exchange information about trackers of a given file. It is another way of ensuring that the file is downloaded from the optimal source. Deluge lacks this functionality.
Con No embedded tracker
An embedded tracker allows turning the client into a server offering an easy way of sharing files with others. Deluge lacks embedded tracker support so another method of sharing or different client has to be used to share files.
Con Lacks µTP transfer protocol support
Con No super-seeding support out of the box
Super-seeding is an algorithm used to allow downloaders become uploaders quicker. Deluge lacks support for this functionality out of the box. However, the ltconfig plugin can enable this setting: http://forum.deluge-torrent.org/viewtopic.php?f=9&t=42887.
Con No built-in broadcatching support
Broadcatching is a method of automatically downloading content as soon as it's available. Broadcatching in BitTorrent clients is usually implemented via RSS. Deluge requires manually selecting each download by default. Fortunately, there are multiple plugins available that add this functionality with the possible caveat of plugins not having the same quality standard as the client itself.