Optimizing µTorrent (or BitTorrent) For Speed

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Optimizing-utorrrent-speed-uTorrent-iconThis guide shows how to speed up downloads in the freeware bittorrent client,  µTorrent. All bittorrent programs need to have their incoming and outgoing communications flow freely in order to achieve the highest download speeds and that is what this guide is about.  This guide will also work for users of the BitTorrent client as the µTorrent and BitTorrent clients are identical.

This guide was put together using information given by the developers of bittorrent programs at their forums, guides and FAQs. There are no secret tricks, just the real basics of proper set up of a bittorrent program. Following these simple steps should result in increased download speed.

These are the basic principles of optimizing a bittorrent client, like µTorrent, for speed: 

  • Choose a proper port to avoid ISP blocks and conflicts with other programs
  • Forward that port through any software firewall and router to allow incoming connections
  • Adjust internal settings based upon upload capacity of the internet connection to allow room for outgoing communications and to distribute upload efficiently. 

There are some programs that claim to optimize speed in µTorrent.Such programs are a scam and generally contain adware or spyware. I have seen it said, by the developers of all bittorrent programs, that nothing will increase your download speed in a bittorrent client more than the basic steps set forth herein.

This guide will work for all versions of µTorrent and BitTorrent 6.1 (and later). Screen shots are from µTorrent 1.8.2 as the options menus had been changed starting with that version.

If you are looking to increase your download speed in µTorrent for Mac, see Optimizing µTorrent For Mac.

If you are not using µTorrent or BitTorrent, there are several other specific guides for other clients and a general guide here:
Optimizing Bittorrent Clients

There are several other help articles for and BitTorrent here at Gizmo's.  A listing is on this page:

µTorrent & BitTorrent Help

Choosing A Proper Port

To avoid messing up a network connection that is already cleared, first check and see if your communications are blocked or are already clear.  Have µTorrent running while you test the port.

The port that µTorrent uses is at Options>Preferences>Connection
The port number in your µTorrent should be entered at the port test site.
The Randomize port each start option should be disabled as this could affect router and firewall settings and rarely serves any useful purpose.


Enter the port number from your µTorrent here at the test page and press "Check":


Click to Test Your Port Success-just go to Adjusting Internal Settings.Error- follow all steps.

If you failed the port test above, then you should first set your port to a proper one.The most important choice here is to avoid using a port within the 6881-6999 range. This was the range originally used by bittorrent programs and is often blocked by Internet Service Providers (ISPs). (If your port was in this range, change and re-test).

The safest choice is a port in the 49160-65534 range as this will avoid ISP blocks and possible conflicts with other applications.  This range used to be 49152-65534, but apparently Vista and Windows 7 grabs some of those ports in between.   Vuze-Wiki: Port is Blacklisted

Windows users, if you want to make certain there is no conflict.  Go to the command prompt and type in netstat -a >c:\log.txt and the press "Enter".  This will check to see which ports are being used and save a text file called "log" at C:\.  Looking at the log.txt file, you will know which ports to avoid.

Forwarding The Port

A router will block incoming communications unless an exception is made. All software firewalls will block incoming communications and most will also block outgoing communications, unless an exception is made. If you are "firewalled", then other people will not be able to initiate connections with you (see Why Is Being Firewalled Bad).
As there are many firewalls and routers, this guide can not give explanations as to each. However, there are guides available, on the internet for most firewalls and routers and this guide will link you to them.

Software Firewall - The permission should be set to allow TCP and UDP in both directions. Generally, you will have a choice to set permission for the µTorrent port or for the µTorrent program. Setting permission for the port is the safer choice.
If you are using Windows Firewall, then all you have to do is go to Options>Preferences>Connection in µTorrent and enable the Add Windows Firewall exception option.

Otherwise, you can check these options for guides:

Router - There are two choices here.  The easier way is to use UPnP.  However, this has a possible security issue.  Using UPnP allows any program to create a port mapping through the router without consent of the owner.  Note:  Given the recent findings of Rapid7 regarding security flaws in UPnP, it is generally suggested here that manual forwarding be used.  If you still want to use UPnP, then it would be a good idea to test and see if your device is vulnerable to attack through UPnP.

The other choice is to manually forward the port through the router.  This does not have that security issue, but involves going through several steps to accomplish.  Using the guides linked herein, this should not be that difficult and is the preferred method.

UPnP (NAT-PMP in Apple) - The Easy Way Enable UPnP (NAT-PMP in Apple) in µTorrent and router.



Manual Forwarding-The Preferred Way

  1. UPnP (NAT-PMP) Must be disabled in µTorrent (see image above)
  2. Use the Static IP Guide
  3. Set permission for µTorrent port. This should be set to allow both TCP and UDP communications.
    You can check these options for guides:

Click Here to Re-Test Port Success-Proceed to next step. Error- re-do steps or seek help in Forums.  Have µTorrent running while re-testing the port.

Adjusting Internal Settings

The most important setting here is to cap upload in µTorrent to 80% of your overall upload capacity. Setting upload in µTorrent is a fine line. The more upload you give, the more download you will get from other peers. However, if upload is set too high, or to unlimited, then download speeds will suffer as outgoing communications (acknowledgment signals, resend requests etc) will be interfered with. Other adjustments are made here to distribute your upload so that you receive back the most download from other peers.

Note:  (Thanks to Roderunner for reminding me of this)

µTorrent does have a built in speed test and Setup Guide (Options>Setup Guide) that will automatically adjust settings in µTorrent. This is a slightly quicker process than this guide.  However, my testing of the Setup Guide settings versus the calculator of this guide showed better speeds with this guide. 

First of all, the setup guide only offers settings for certain upload rates.  So if your upload rate falls outside their offerings, the settings will not be as precise as those in the calculator below.  Even if your upload rate matches one of the offerings exactly, the automatic settings of µTorrent for that rate are not as effective as the ones given by this calculator.

There is not much more involved in entering the settings from the calculator into µTorrent and the increase in download speed will make it worthwhile.

Speed Test: Speedtest.net (Click for Test)
First the upload capacity of your internet connection must be determined by taking an online speed test. Speedtest.net has test locations worldwide and will highlight the one closest to you.
To take the test you must have Flash installed and javascript enabled.

Before taking the speed test, press Settings in the upper right of the speedtest.net page.  This will take you to another page.  At the bottom of that page is the "Global Settings" options.  Set "Speed Measurement" to kilobytes and press "Save" .  This will facilitate entry into the calculator below and will lessen confusion as µTorrent shows speeds in kilobytes.





You should stop all internet activity, including torrents, before taking the test and the test should be taken a few times to obtain a reliable average. Results will now show in KiloBytes. It is the upload rate that is important here.


Another Way To Test Upload Speed
For most people these test results will be reliable (Comcast users see Note). However, you may wish to do a double check on real life upload speed. When you are active on a torrent with a good number of peers and you are using your upload cap, set upload to unlimited and watch for about 5-10 minutes and see where upload settles in at. Then input that number into the calculator in the kiloBytes section. 

Note: Some ISPs will show inaccurate results on the speed test. If your ISP has anything like Comcast's PowerBoost, then your results will show higher than the actual speed of your connection. PowerBoost provides a burst of download and upload speeds above your provisioned download and upload speeds for the first 10MB and 5MB respectively. Since the speed test involves relatively small files, this will skew results upward.
If you have PowerBoost, or something similar, my findings from my own results and those of others is that the actual speeds are 60% of the test result.  So if you get 200kB/s for upload at the test, you should enter 120 in the kB/s box in the calculator.  Using Google ("speed result" x .6) will get the proper number to enter in  the calculator and this actually turns out to be very accurate.  You should end up with the calculator showing a cap that is about half of the test result.

Calculator Azureus Upload Settings Calculator
Once you have an average upload speed for your connection go to the online Azureus Upload Settings Calculator. Although designed for Azureus, this calculator will work for all bittorrent clients.
This calculator was created by the8472 a contributor to Vuze (fka Azureus) and part of the team that created Bittorrent Protocol Encryption.

Enter your average upload speed in the appropriate box


The calculator will automatically give the proper figures to adjust various options in µTorrent.


Input Results Into µTorrent - Screen shots of locations in µTorrent of settings to be adjusted 



Peer Sources & Encryption

Having the proper peer sources enabled, such as Peer Exchange (PEX) and Distributed Hash Table (DHT), will help download speeds as they will help you find additional seeds and peers for a torrent.  Local Peer Discovery should be enabled as it supposedly searches for peers on your ISP or those on an extended network or on a LAN party. it can be very useful on a LAN party.  I have not found it to make much of a difference when not on a LAN or extended network.

Encryption was primarily designed to thwart Internet Service Providers interference with bittorrent.  Having encryption enabled and allowing incoming legacy (non-encrypted) connections will provide you with the largest pool of seeds/peers to select from.

These settings are at Options>Preferences>BitTorrent and should be set as in this image:


Good Torrents

The general rule here is to choose torrents that have a high seed to peer ratio. Seeds have 100% of the content associated with the torrent and are only uploading to peers. Peers also upload to other peers, but are also looking for other peers to upload to themselves and their download capacity is almost always higher than their upload capacity.

This applies even though one swarm has significantly more active users than another. For example, a torrent with 30 seeders and 70 peers (30% seeders) will generally be faster than one with 500 seeders and 2500 peers (20% seeders) as the average upload capacity available to the peers will be higher. (TorrentFreak).

For more information see Good Torrents

Related Articles

Gizmo's Best Ever Freeware Forums

If you still have issues after using this guide and would like some assistance, you may post here or our Forums.  The comments section here is not well set up for ongoing discussions, so the forums are a better place.

When posting on a speed issue, please provide

  • Your speed test result for both upload and download speed in kiloBytes per second (kBps)
  • Your result at canyouseeme, both before taking any steps and after.  Just indicate Success or Error do not post your IP address.

If you have a suggestion or correction for the guide, please post here.

Those who wish to post a thanks may post here or in the forums. I always appreciate hearing from those who this helped and I do read the posts regularly. I used to respond to each thanks, but realized it was clogging up the comments section. I thank all those who have posted their appreciation and all those who will.

So, to those who post a "Thanks", I appreciate it.



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by Noctix (not verified) on 10. March 2011 - 11:35  (67734)

Hey man thanks for the guide, I thought my speed was good but it increased by 10 times almost on a certain torrent I've been trying to download.


by frozenfire (not verified) on 15. March 2011 - 8:06  (67943)

thanks very much port 50566 works,,..XD

by Capteasy (not verified) on 29. March 2011 - 3:17  (68726)

I wish to thank, and commend the good work you gentlemen do.
I'm an old %$*)#%_# AND am learning new tricks.
Been downloding stuff for my grandkids to watch(having a blast).
I read until my eyes give up.
Thanks ever so much.

by cal (not verified) on 15. April 2011 - 0:34  (70211)

I'm crusin' now daddy-o! thanks

by Anon234 (not verified) on 16. April 2011 - 3:21  (70285)

I did follow all the steps (at least, I think I did) but there wasn't any change for me D: I'm on bayandBROADBAND's plan 512 (512kbps).

On speedtest, my down rate is 112.4kBps while my up is 81.5kbps.

The averaege downrate of my torrents are at about 67kB/s. Does that make sense? Is that normal?


by mr6n8 on 16. April 2011 - 7:13  (70294)

ISPs advertise speeds in bits (b) and uTorrent shows speeds in bytes (B).
8b = 1B so 512kbps = 64kBps

So the 67kBps is right at your max.

Not sure why the speedtest is showing 112.4kBps.
I looked to see if your ISP has some sort of speedboost, but I could not find any info at their site.

So you are running as fast as you can.


by Pein (not verified) on 19. April 2011 - 20:44  (70559)

THNX man u r brilliant!!!!!

by Bama Boi (not verified) on 23. April 2011 - 5:31  (70744)

Awesome! Thanks. My download speeds using uTorrent increased drastically after following this guide. I thought it was the torrent itself when I was downloading a maximum of 30-40kbs until I knew something was wrong. Now I am capping out around 1mbs.

by commentator (not verified) on 4. May 2011 - 21:36  (71427)

thanks man
but i have one question, should i enable bandwidth management (uTP)and UDP tracker support as well or keep them disabled. This options show up in the new version of utorrent

also what about automatic port mapping??

by mr6n8 on 4. May 2011 - 23:03  (71431)

I am glad you asked these questions as I had meant to check on those new options and had forgotten.

As far as UDP tracker support, the answer is yes enable.
Previously uTorrent did not support UDP trackers and there are more out there now. Certainly no harm can come from using this and some good can.

The "bandwidth managment (uTP)" is the one I was not certain of.
The help file says:
"Enable bandwidth management allows µTorrent to use uTP to try and gain a better sense of how much bandwidth it should be using while maintaining quality of Internet service."
The uTorrent site says:
"µTP works to maximize network throughput while reducing network latency and congestion - it is designed to slow itself down when the network is overloaded (when sending and receiving would only make things worse!) - the result is a win-win of faster downloads for users with lower network impact for both users and ISPs"

Now that sounds good, but a lot of this has to do with uTorrent (and its parent corporation-BitTorrent) wanting to present an image of getting along with ISPs. That does not mean that enabling this option will result in the best speeds for you.

I have tried both with and without the option enabled on quite a few test torrents and I have not found a difference.
Some claim it slows speeds.

Others think that uTP is bad for speeds overall

I am not sure. People tend to be resistant to change and make unfounded statements. My tests of uTorrent for the Best Free Bittorrent Client review showed uTorrent to be as fast as ever. Maybe, it relates to the ISP.

I am leaning toward having it disabled, but am not certain.
In any event, I have not seen it makes much of a difference.

As far as "automatic port mapping"-I am not certain what you are referring to.
Are you referring to UPnP port mapping under Preferences>Connection?
If so, the plus and minus of that are discussed in the guide.
If not, let me know.


by Sheldon Braganza (not verified) on 11. May 2011 - 13:20  (71770)

Brilliant explaination! increased the download speed drastically. Thanks

by Hellion (not verified) on 18. June 2011 - 22:12  (73971)

Great job! I just finished doing this and I had a torrent that was scheduled for DL in 1 day and 7 hours, as soon as I changed the settings it went down to 5 hours! You ROCK!!!!!!

by Soumya Sharma (not verified) on 5. July 2011 - 5:57  (74768)

you rock... my speed has greatly improved!
tanx a tonn... :)

by Hellyer (not verified) on 22. August 2011 - 1:56  (78121)

Have to say thank you very much for the guide. If speeds stay as they currently are my speeds have gone from around 50-80 kB/s to 200-300 kB/s. Now if I could just get my ISP to stop booting me every 15-20 minutes. Any suggestions? This only happens when downloading/uploading torrents.

by kieran9669 on 29. August 2011 - 10:13  (78547)

thank you so much for this guide, my speeds went from about 24kbs, to around 1.1mbs, best utorrent guide around!

by Thankful (not verified) on 10. September 2011 - 5:43  (79348)

I went from 250kb/sec to 1.3MB/sec because of this article. THANK YOU!

by Appreciate (not verified) on 10. September 2011 - 19:29  (79380)

Thank you so much for this great info! People like you make the internet better for everyone. Cheers!

by Anonymous12231 (not verified) on 17. September 2011 - 12:38  (79785)

thanks so much from 10kb/s - 1.1mb/s ;)

by gaminGeek (not verified) on 18. September 2011 - 3:47  (79826)



by sami bangash (not verified) on 21. September 2011 - 6:24  (79999)

thanks a lot. speeds definitely improved now... but just wanted to know that since u torrent is a p2p sharing network, does that affect ones dedicated download/upload speeds on u torrent? i checked my speed at speed test and it gives 56KBps download(thats okay cuz of my dsl package limitations) but all m getting max is 45 KBps in torrents... i also observe that the speed fluctuates every second a lot which is pretty annoying... although it gradually evens out after a while downloads into progress.....

by mr6n8 on 21. September 2011 - 11:29  (80015)

There is some loss of down speed due to bandwidth being used for communications with the tracker(s) and other bittorrent clients active on the torrent.
The difference on yours seems to be a bit high. With slower internet connections it may be necessary to lower upload to 70 or 75% of overall upload capacity to achieve optimum download speed. This may or may not make a difference for you.

Each torrent has its own speed parameters as your download speed depends on the upload capacity of other active users and also whether these users have cleared their bittorrent client through the firewalls in their system. So it is difficult to judge the max download speed of your bittorrent client on your internet connection from one torrent.

As to the speed fluctuating at first this is pretty common in bittorrent. The bittorrent process involves communicating with the various peers and seeds and there are some drops until your client and theirs decide which are the best to stay connected to.

There are often similar issues near the end of a download as fewer active users have the remaining bits needed for you to complete the download.


by cho-cha (not verified) on 22. September 2011 - 17:44  (80124)

my port is open and fine..its my my upload speed..when im in a good sutiuation..i notice my upload speed going up and down..it flictuates alot..never consistant..i also have an http 404 error in my loger for utorrent.
i failed the speed test thats built in to the interface host.

by cho-cha (not verified) on 23. September 2011 - 4:48  (80156)

by the way,thank you for this page..it is really good and i read it tonight for atleast 2 hrs..great stuff.

by Irma Dalakanitzkova (not verified) on 16. November 2011 - 21:52  (83403)

Congratulations on the guide,

Which presents the information very nicely. Then again, one can only wonder if people ever read manuals, help files, FAQ or the like, because this is the same .torrent 101 that can be found on each and every blog, forum, website, whathaveyou ever written about the BitTorrent format: open a port for incoming connections, forward it through router and firewall and set your speed limit for uploads to 80% of the maximum possible outgoing throughput.

Contrary to all the leechers around here, the real problem with BitTorrent is not the speed of downloads, but uploads. Yeah, if you merely hit & run you couldn't care less, but nice, responsible virtual citizens seed at least as much as they download. Unfortunately, 99% of all broadband connections around the world are asynchronous, i.e. download speeds are 6-10 times higher than upload speeds. This means that one can leech a couple dozen GigaBytes rather quickly, even with non-optimized settings, but there is no way in heaven one can upload half that amount quickly enough to avoid getting banned from fora and trackers. It happens all the time: people are so fixated on getting stuff quickly that they totally forget that actually, the total time for obtaining a torrent is download+upload to at least a 1:1 (100%) ratio, within 28 (sometimes only 15) days. Otherwise, the other members of the community, administrators, moderators and automated pruning mechanisms have you banned and blocked before you can get out of the hole.

The really interesting question is therefore: which (advanced?) settings and options must be tweaked to which values in order to upload as fast as possible, to as many peers as possible? Downloads will always be (relatively) quick, but it is the Damokles sword of ratio that strikes if seeding speeds and uploaded volumes are not kept in balance. So, how to maximize the seeding bandwidth?

Any tips & tricks for that? It doesn't matter if downloads are affected adversely, it is the maximum stream upwards that the smarter members of fora/trackers are after. In case optimizing the system to that end requires the exchange of confidential details (and because one cannot visit all tech sites on the web continuously), feel free to send an e-mail to Irma_Dala1937 (at) live (dot) co (dot) uk

Thank you very much for the very nice guide and keep up the good work.

by mr6n8 on 16. November 2011 - 22:33  (83404)

Some very good point in your post.

As to the guide, it is as I say in the beginning and as you have said, the "real basics" of bittorrent. Unfortunately, people are always looking for the magic pill that will send down speeds skyrocketing. I put the guides here up to battle those who offer those magic pills (that do not work). The main purpose of this guide is to present the basics in an easy to understand manner and all in one place information.

And you are also correct regarding the asynchronous levels of down versus up on the vast majority of connections. To be fair to ISPs, no one ever anticipated that the average user would use much upload. P2P is fairly recent and changed all that. One of the advantages of bittorrent over traditional P2P is that the numbers overcome the disparity as far as download speed.

As to the last issue, maximizing upload, unfortunately there is no magic pill for that either. When down speeds are 6-10 times greater than up, the problem is with the pipes delivering the goods. This issue is a big one for private sites and is worsened for the average user by the one avenue of correcting the disparity: Seedboxes.

Seedboxes pretty much have equal up and down and can deliver tremendous upload speeds. Unfortunately, this ends up locking out the average user from any upload as the seedboxes dominate when someone downloads. Private sites have begun to realize this and are moving away from ratio to just enforcing hit and run rules. Most of the upload credit that the average user gets at a private site nowadays is from the bonus points/bytes given for keeping the torrent active, even when not uploading.

Other than seedboxes (which of course cost money) the basic settings are the best that can be done for upload as well as download. For instance, the limiting of upload slots ensures that you have enough upload bandwidth to give to each peer so that they stay "interested" in you. But if there is a seedbox that can deliver upload that takes up the maximum download capacity of a peer, that peer is not going to bother connecting to a non-seedbox user.

Thanks for the interesting post. Always nice to hear from a knowledgeable and considerate user.


by Roderunner on 19. November 2011 - 16:47  (83549)

Very nice tutorial, but its not required except for the setting of port numbers.
If you double click the green ticked icon on the bottom right hand corner in Utorrent, it will check and store the settings for you automatically. As I have Outpost Firewall Pro.it was disabled before running the test.

by mr6n8 on 19. November 2011 - 17:25  (83551)

Yes that will get access to the "Setup Guide", which is also available through Options>Setup Guide.

I used to have a note in the guide about that. Somehow, it is not there now (I probably used the wrong backup at one time). I will add in under adjusting internal settings. What it will say is basically this:

uTorrent does have a built in speed test and Setup Guide (Options>Setup Guide) that will automatically adjust settings in uTorrent. This is a slightly quicker process than this guide. However, my testing the settings of the Setup Guide versus the calculator of this guide showed significantly better speeds with the calculator settings in this guide.

First of all, the Setup Guide only offers settings for certain upload rates. So if your upload rate falls outside their offerings, the settings will not be as precise as those in the calculator below. Even if your upload rate matches one of the offerings exactly, the automatic settings of uTorrent for that rate are not as effective as the ones given by this calculator.

There is not much more involved in entering the settings from the calculator into uTorrent and the increase in download speed will make it worthwhile.

Thanks for the post as some users will prefer the ease of the setup guide over the efficiency of this guide.


by Maloof (not verified) on 19. February 2012 - 12:52  (89048)

Holy $H*^ it worked!

I just had to read, re-read, then follow instructions. Easy as that. The biggest problem was my own fear of screwing something up.

A billion thanks for all of the great explanations and tools that you provided. You are awesome and I wish you the best!

by Hassan AQ (not verified) on 29. February 2012 - 8:11  (89685)

your explanation was excellent. i followed all steps now i am getting good constant speed. thanks a lot.

by Patricio (not verified) on 7. April 2012 - 4:42  (91734)

Thank you for this! Very useful!!!

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