Best Free BitTorrent Client

Since its inauspicious public appearance just under 12 years ago  bittorrent has become one of the major download formats. With good reason too: it's fast, equitable and efficient. For the downloader, bittorrent offers an uncorrupted copy of the original with the option to stop the download at any time and re-start from where the download left off (very useful for those on shaky internet connections)
f you haven't yet installed a Bittorrent client on your PC, you should as there are some great freeware clients available.   In Bittorrent the best clients are free.  (In fact, if a client costs money, it is most likely a scam).

This article is part of a series of articles on bittorrent here at Gizmo's Freeware.  If you are not familiar with bittorrent, then before using this article you should read this:

• How To Use Torrents 

There are setup guides here at Gizmo's Freeware for each of these suggested free bittorrent clients.  Links to the guides are with the product description in the Quick Selection Guide at the end of the review.

This review was prepared on February 8, 2013, and the testing was conducted in the two weeks before that date and used the latest versions of the clients at that time.

Testing

Anyone with knowledge of bittorrent knows that it is nearly impossible to have a testing procedure that is foolproof in measuring small differentials in speed among bittorrent clients.  This is due to the fact that your download speed depends on the upload of other active users and there is no control over their actions while testing.  However, I have been testing clients for this category for several years and am convinced that the better clients can be separated from the others.

There were 7 rounds of testing to boil down the 17 clients tested to the 7 in the review.    Six torrents and three magnet links were used in this part of the testing.  I then conducted several tests in two rounds of testing to determine the Top Pick.  I did post pdf copies of my notes for each round of testing:  Bittorrent Testing 2013 Notes

All of the clients listed in the review had excellent performance on all of the testing, so all are superior bittorrent clients.  The speed performance on the testing was a factor.  Even though the speed differences were small, some consistently performed slightly better.  Features and support were also factors.  CPU and RAM mattered in that a client without many features that had high CPU or RAM use would fall to one with low CPU/RAM use.  Toolbars and addons in the installation process were a slight factor.

Testing was performed on Windows 7 64bit.

About Me

I am not a technical expert, but I  have been using bittorrent since 2003.  Before coming to Gizmo's I was the Administrator at a general bittorrent forum site, giving assistance on a variety of clients, and a moderator at the Vuze fora.  I still view a number of bittorrent fora and the fora of the various bittorrent clients.  This gives me a good idea of what the average user is looking for in a bittorrent client.

Ranking

All of these clients have the basic bittorrent features like DHT, PEX, encryption and UPnP. 

All seven of the bittorrent clients listed here performed excellently on all test torrents.  Speed and performance was a factor, but features and support facilities were major considerations.  A clean installation (without toolbars or ads) was a plus.

Most people just want a client to download torrents, but there are some features that a number of users like to use, such as a built in IP Filter, use of RSS feeds, proxy support, a scheduler and a web interface.

I will make note of those that have installs or other changes to your system that are not necessary for the proper function of the bittorrent client.   I strongly suggest that if you choose a bittorrent client that has these unnecessary add ons, to not accept those changes or add ons.  I have put up guides to help with the installation of the three clients that have these unnecessary steps in the installation process.

 All seven of these clients performed excellently on all the test torrents and any one of them will meet your needs as a bittorrent client.  There was some slight download speed differentials, but nothing too significant.

Tixati is the top pick this year as it runs fast, offers a lot of information and has the most appealing interface in a very efficient package, RAM and CPU wise. 
Tixati always seems to be in active development and the developers are receptive to users input.  The wide variety of layout options are indicative of their responsiveness to users.  Tixati has all the features that an average user wants.
Their help facilities have grown, but have gotten a bit out of date..  Their forums are responsive,
I was surprised to find that Tixati does not support web seeds.  Generally not an issue, but there will be an issue with the 3 million torrents at Archive.org as many of those are seeded by web seeds. 
Many users will like the colored display and the many options for display as well as the vast amount of information offered within a program that uses relatively little system resources.  The clean install will appeal to all.

Pros:  Stable and efficient with a good variety of options.  Developers are active and responsive to user requests.  Attractive interface.  Good help resources.  Clean install.

Cons:   Help resource, though very good, could use some updates.  No support for web seeds.

qBittorrent is the choice for those users that just want to download torrents and are not interested in graphs, extra information and display.  qBittorrent tested slightly faster on the test torrents consistently.  Its RAM and CPU use make it the most efficient client here.
It has all the features that an ordinary user would want. Their built in search runs quick and has a good number of sites included at default.  I am usually not a big fan of built in searches, but this one is superior to the rest.  Plugins for additional sites are available.   
The Wiki  has improved, but is not among the best..  The situation at the forums is good.   Response at their bugs page is excellent and the responses are from the developer.  
qBittorrent has been the Top Pick here at TSA for a few years and was only a sliver behind Tixati this year.  This is an excellent client that is fast with all the features an average user needs with small CPU and RAM use and a clean install.

 Pros:  Low and stable RAM and CPU with all the necessary features.  Fastest performance on torrents.  Development still seems to be very active and responsive to users.  Clean install, no addons etc.  Cross platform client.

Cons:  Support has improved, but could be better.   Not that well known and not accepted at many private torrent sites (though the situation is improving).

These next three clients include toolbar offers, home page and search engine changes and additional software offers during installation.   I suggest that you decline all such offers.  Since I have seen so many users complain of the toolbars and changes taking effect after installation, I have put up guides (see Quick Selection Guide)  to avoid these unnecessary extras,

Vuze  is a good choice for those users that utilize a VPN or proxy, due to its options that can stop all activity off the VPN or proxy (useful if the VPN/Proxy goes down) and its option to disable IPv6 support (for VPNs that have an IPv6 leak.
Vuze is still an excellent client with a wide variety of plugins  and options and information.   They were the first bittorrent client to add streaming capabiities.
Their help resources (Vuze-Wiki and Vuze forums) have taken a step back, but the Wiki is still an excellent source of information and the fora does provide decent support. 
Although the client has improved its RAM use greatly since the Azureus model, it still is the big RAM user here, though this is really not an issue in this day and age.
Their install includes a toolbar and home and search page changes enabled at default.  There is also a software install offered  and it also has advertisements in the Vuze portion of the client (can be avoided by  using the "Classic" interface).
Many users like the intricate details this program provides, its streaming capabilities and its VPN and Proxy support is superior to other bittorrent clients.

Pros: There is a wide variety of options and information within the program and an impressive array of plugins to satisfy any need.  Support for VPN  and Proxy use is superior.   Streaming capability.  Cross platform. 

Cons:  Toolbar install and home page change enabled at default on install.  Advertisements within free version of Vuze interface (can be avoided by using Classic interface).  Highest RAM use of the clients here.

µTorrent has been top pick here in the past and is still a superior bittorrent client.
With the excellent results on the test torrents, the fact that it is a stable and low resource using client and the vast amount of features packed into this tiny program, this is a top flight bittorrent program.  
The support provided by  µTorrent's FAQs, guides and forums is excellent, though it has diminished a bit from past years. 
Streaming to devices capability has been added in recent releases.
µTorrent does try to foist a toolbar, home page change, search engine change and a software download during install.     Recent versions of µTorrent have been in disfavor at many private sites, supposedly for reporting to the tracker issues.
µTorrent has become by far and away the most popular bittorrent client due to its small, efficient, feature filled package.

Pros:  Excellent speeds on torrents, efficient and stable client with a large amount of features packed into a tiny package.  Excellent help resources. Streaming capability.

Cons:  Has had critical security alerts at Secunia. (though none on this version).  Toolbar install (not necessary for program) and search/home page change enabled at default on install.  Unnecessary software offered during install.   Recent versions of µTorrent have been in disfavor at many private sites, supposedly for reporting to the tracker issues.

BitTorrent.  Everything I said about µTorrent, above applies to BitTorrent as the two are identical in their options and engine.  Both are owned by BitTorrent, Inc., and are developed by the same development team.  If you prefer the name BitTorrent and its purple color over the µTorrent name and its green color, then that would be the only reason to choose this client over µTorrent.

Even though the two clients are the same, BitTorrent is still banned at most private torrent sites (even though they accept µTorrent). 

Like µTorrent, BitTorrent is a small and efficient bittorrent client with a great deal of features and will appeal to many despite the "extras" in the installation.

These last two clients offer a clean installation and performed excellently on the test torrents.  Their lack of support and some features is the reason they are last on this review.

Transmission-QT (Windows) is a basic bittorrent client that runs fast and has a simple interface.  It is missing some features and does not have much support.
This is not an "official" release of the Transmission team, but has been touted in their forums for years and now has its own site at Sourceforge.
Not quite as efficient, RAM and CPU wise as some of the other offerings here that have more features.
The clean install and basic interface will appeal to those who just want to download torrents and do not need any bells and whistles.  This Windows port of Transmission will give you speed with the best.

Pros:  Efficient and stable with excellent speeds.  Simple interface.  Clean install, no addons etc.

Cons:  Not an "official" release of the Transmission team and is lacking help resources.  Missing some features

Halite has the smallest RAM use of the seven clients.  It is a clean, small and fast bittorrent client, but lacks some features and has almost no support facilities.  If you just want to download torrents on a client with a simple interface, the Halite is a nice choice.
Halite was off this list in last review as it had not been updated within a year.  The version tested here was released just prior to the testing for this review.  So, there is some uncertainty for continued updates. 
This is a good client for those who want a simple, no frills bittorrent client.

Pros:  Small, efficient and fast bittorrent client.  Lowest RAM use of the suggested clients.

Cons:  Missing some features.  Support is weak.  Releases have been sporadic.

  A full listing of the bittorrent help pages here at Gizmo's Freeware is now at

• How To Use Torrents

There are also links to the guides for each suggested bittorrent client in the Quick Selection Guide below.