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 mr6n8 on 3. January 2010 - 13:17  (40128)

Sounds like it is not an issue on your end.

In bittorrent your download speed is limited by the upload speed of the other active users. Most people in the world have slow connections and very low upload capacity. Also, most people have not cleared their network connection or set up their options to distribute their upload properly.

The 6MB/s you saw in uTorrent is 48Mb/s (8b = 1B) so that is pretty close to your speed test result. That torrent has some dedicated servers with good upload rates on it all the time. Even so, you probably maxed them out.

Anyhow, since you got that and the 4.2MB/s, it looks like your set up is OK. Most likely it is the lack of upload speed of the other users that is limiting your speed (although I often get above 600kB/s on my torrents).


by Anonymous on 13. January 2010 - 18:32  (40972)

Hi, thanks for this great info. I followed all the steps, but I'm a bit confused. I cant get a success when I check the port. I've tried several different ones. I'm confused because the static ip address i set up is not the same as the ip address that comes up on the port test site. Is that normal? I'm so frustrated. I have Mcafee, Uturrent has full access and I even disabled it to make sure that it wasnt the problem. I have the red icon at the bottom that says its still being blocked. Is there anything else that may be blocking it?

by mr6n8 on 13. January 2010 - 20:06  (40975)

"I'm confused because the static ip address i set up is not the same as the ip address that comes up on the port test site. Is that normal?"
Yes. The static IP is an internal address for your LAN. The one you see at the port test site is your external IP address.

As to the blocked port, we can assume it is not McAfee as you have disabled that and the port was still blocked.

I assume since you set a static IP that you have a router. Did you set exception in the router for uTorrent?

Do you have any other security software besides McAfee?

Who is your Internet Service Provider (ISP)?


by Anonymous on 14. January 2010 - 8:11  (40999)

I did set the exception on the router. I tried it twice with two different ports and Static IP addresses. I looked for other security software and found none. I have comcast high speed cable internet. Its 2am and Im currently downloading a 7.85 gb torrent. It reads 22(301) seeds 48(1974)peers and im down loading at 87 kb/s and uploading at 33kb/s (I already set the max upload). Is that a normal speed? should I even be worried? It seems that the speeds went up slightly sicne I did everything but it is still red at the bottom saying that is is blocked.

by mr6n8 on 14. January 2010 - 11:47  (41006)

On that torrent you are connected to a good amount of seeds and peers. That part looks like it should with a clear network connection.

The speeds could be normal, but looks a bit low.

Comcast is not a port blocking ISP. If they do interfere it is in other ways.
I know the icon is red, but are you also failing at canyouseeme?
Just as a test of whether the forwarding rule in the router was done properly, you could try using UPnP.
What is the make and model of the router?
Also, what is the make and model of your modem?

What was your result on the speed test and what did you cap upload at?

by Anonymous on 14. January 2010 - 14:08  (41009)

Yes, I've failed canyouseeme both times. I have a dlink DI-624 and the modem is a motorola SB5100. Actually, when I checked the model of the modem I realized that I also have a vonage (the cable voice over internet company) device connected to the modem. It then connects to the router so its in between the two. Could that be it? Whenever utorrent is running my phone calls become very scratchy. Duh, that has to be it huh? My speed average was around 46-47 so I set it at 36 limit per azerus. Whether i get it working or not Id like to thank you again for your help.

by mr6n8 on 14. January 2010 - 14:28  (41010)

Dlink routers do have some issues with bittorrent. They sometimes have trouble with the amount of open connections and the DI514 had some port forwarding issues.

But the 624 issues are only with too many open connections from bittorrent client and that is not your issue as that would cause disconnects.

I also have the SB5100 and that has no firewall and is not the issue.

I do not think the Vonage is an issue on the port. I am not familiar with Vonage, but most of the VOIP use UDP transfers and so does uTorrent. The issue is generally on the upload bandwidth side. You might try lowering upload in uTorrent just a bit more and see if that helps.

That upload is pretty low for a comcast connection, but it is what it is.

I am not sure what is going on in your situation, but usually a closed port causes issues in getting connections to seeds/peers. As I said before, your connections on that torrent are very good. It is hard to say if that speed is normal as each torrent swarm has its own speed rules (as the bandwidth is provided by the active users).

I can not see what would be causing the issue. You are the 3rd person with McAfee that I have seen this situation (the other two were not connecting to seeds/peers as you are). But I have found nothing on McAfee that would cause that.

I can only suggest two things at this point:
Do nothing more as it looks like you are getting good connections with seeds/peers-
Or, try deleting McAfee and try some of the freeware alternatives here. Sometimes (for reasons unknown to me) these troublesome security ware issues can only be resolved by uninstalling and not by disabling. Again, I do not know of any issue with McAfee like this, but it is possible.

My pleasure to try and help. I just hope it ends up doing some good.

by Anonymous on 14. January 2010 - 15:11  (41013)

Well, I disconnected the vonage box and went directly from my modem to my router. Voila, green dot. It seems faster, but now my phone doesnt work. Tough choice. I guess, I'll have to find a new way to connect the things. Any suggestions. Thanks.

by Anonymous on 14. January 2010 - 15:23  (41016)

Another update, I have a green dot on the bottom of utorrent which says the connection is good but when I check the port it still says it is blocked. Ugh. I think I just have to go with the flow. Thanks.

by mr6n8 on 14. January 2010 - 17:17  (41023)

I misunderstood your first post on this. I just re-read and saw that the Vonage box was in between modem and router. I am not at all familiar with that kind of VOIP (I use MagicJack), but I would think you could hook it up to the router.

by mr6n8 on 14. January 2010 - 17:19  (41024)

If it is showing green in uTorrent, I would think you are OK.

Are you testing at canyouseeme or through uTorrent?
Do you use any IP filter blocklist?

Are you checking while uTorrent is open?

by Anonymous on 15. January 2010 - 15:02  (41109)

I tried it in both. Its all good now. FYI I reconnected the vonage box to the router,just not inbetween the two and now I have a success response. Weird huh, but It works. Thanks for all your help!

by mr6n8 on 15. January 2010 - 16:35  (41126)

That is good to hear.

I'll have to remember on the Vonage for any future issues people may have with it and a bittorrent client.



by Anonymous on 19. January 2010 - 18:12  (41555)


by Anonymous on 31. January 2010 - 10:56  (42465)

Amazing guide bro.. thanks.. :D

by Anonymous on 1. February 2010 - 5:44  (42525)


I have a question. I "forwarded the port" manually according to the instructions above, but still have the same problem as before: after I start uTorrent, it speeds up for a while, then the upload and download speeds drop to zero, and Internet gets disconnected. There are no error messages in uTorrent itself. The connection can only be restored by resetting the router, then it's all over again. Any suggestions?


by mr6n8 on 1. February 2010 - 10:54  (42540)

Hi Nik

Sounds like your router may be overloaded by the number of open connections coming from uTorrent.

What is the make and model of your router?
What was your result on the speed test for upload? and
what did you cap global maximum number of connections to?


by Anonymous on 1. February 2010 - 18:37  (42562)

Hi Steve:

Netgear CG814GCMR
Speedtest: I set the limits to 80% of maximal speed. It is currently set to 817 Kbyte/s download, 105 upload
Global max # of connections: 800
Max # of peers per torrent: 80
# of upload slots per torrent: 80


by mr6n8 on 1. February 2010 - 19:14  (42564)

Yes that is way too many open connections.

Your router is not on the "bad router" list, but any router may have trouble with 800 open connections.

As a general rule home routers can only handle 255 open connections at a time.

Your number of upload slots is also way too high. This will cause your upload to be diluted and result in less download back from other peers. You want to concentrate your upload to get the most download back from other peers.

You should go through the Adjusting Internal Settings section of the guide:

But max global connections should be limited to 200 (if you still get this issue, even lower).

Many people think that more open connections means better download speed, but too many connections can hurt speed. This post by The Shadow (creator of BitTornado and super seeding) explains:

Let me know if you have any Qs


by Anonymous on 5. February 2010 - 15:53  (42889)


Some users may find the above test & tools site useful.
It includes the justly-famous "Glasnost" test to diagnose ISP throttling.
Some of tests take several miutes to complete.

by mr6n8 on 5. February 2010 - 16:20  (42894)

Good post.

I have that on my list to look into.

I tried Glasnost when it first came out and was not that impressed.
However, it looks like they have expanded the tools to test and it may now be a winner.

If it turns out good I will add it into an article.



PS Not sure why you posted down here instead of up top.

Just tried their bandwidth testing program a few times and it incorrectly shows very high for speeds (both upload and download). I wish I could get the up and down speeds it shows.
I have comcast and with its "PowerBoost", speed tests will show high-but not as high as this. This was showing about 50% higher than any other speed test (which already showed high).

by Anonymous on 6. February 2010 - 9:36  (42940)

I posted in a non-ideal place because G's comment system is difficult to use if you don't log in, and I think i'm banned.
So it goes.
I found the mlabs stuff very accurate.
I remember the first versions of your torrent articles here; they were totally great, but the way youve managed to expand and add info to them is quite breathtaking.

by mr6n8 on 7. February 2010 - 12:08  (43051)

Thanks for the good words.

I am testing some new bittorrent clients for the best free review, so it will be a bit before I get to take a good look at Mlab.

by Anonymous on 14. February 2010 - 10:46  (43591)

This was an excellent tutorial, I just about doubled by torrenting time, even though connecting to seeds is still a chore.

by Anonymous on 14. February 2010 - 10:47  (43593)

It also helps (on Windows 7) that you make sure that if you're on a internet connection that you "own", set the network type to home, as it opens up a lot of ports for torrenting. This made my speed go up quite a bit.

by Anonymous on 15. February 2010 - 15:56  (43675)


by mr6n8 on 15. February 2010 - 16:29  (43679)

Not much you can do about connecting to seeds if your network connection is cleared.
Mostly that depends on their setup (whether they are firewalled) and automatic decisions by your and their bittorent clients.

Good tip on the "network type"
Some info on the different "types" and how to change here:

Looks like the default is "public".

I am not a Windows 7 user myself, but your advice sounds right.

I probably will add that information in somewhere.


by Anonymous on 16. February 2010 - 9:33  (43724)

I'm having problem in forwarding the port by UPnP (easy way).I checked it in bittorent (options/preferences/connection i checked both UPnP and NAT-PMP) but i still get the red marker in bittorent indicating that i still have problem with connection.And when i run 're-test port' i get error...I think that my firewall isn't problem (i'm using AVG, windows firewall is disabled).This guide says "Enable UPnP (NAT-PMP in Apple) in µTorrent and ROUTER".How to enable it in router (that is only thing that could be the problem i think)?Thanks everyone how try to help...

by mr6n8 on 16. February 2010 - 10:10  (43728)

What is the make and model of your router?

by Anonymous on 16. February 2010 - 10:31  (43731)

Router is : Tp-link TD W8901G...Thanks for such quick response...

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