Increase Download Speed of a BitTorrent Client

Download torrents faster by tweaking program settings

A screenshot of qBittorrent.

 The qBittorrent Project / All Rights Reserve

It's common for some torrent users to experience slow download speeds, and there are a number of factors that could contribute to that. However, one possibly overlooked reason has to do with the ports that the P2P traffic is operating on.

Since a particular BitTorrent port has to be open on both the router and the firewall to facilitate both incoming and outgoing traffic, users who have both of these might not be using the correct settings to get the most out of their downloads.

The issue is having a firewall that's blocking incoming BitTorrent connections that are needed to share the files. Given the load balancing and swarming nature of BitTorrent, clients unable to take incoming requests for uploads will usually be allowed less bandwidth for downloads.

Ports Are Used to Transfer Data

A torrent client sets up a network resource called a port that allows other BitTorrent clients to connect to it. Each port possesses a unique number called the TCP port number. The client normally associates the 6881 port.

However, if this port is busy for some reason, it will instead try successively higher ports (6882, 6883, and so on, up to 6999). In order for outside BitTorrent clients to reach the client, they have to be able to traverse your network through the port that the client is using.

Whether or not this is possible is determined by both the router and the firewall since both can be set to open and block ports. For instance, if port 6883 is what the client is assigned to use for uploading data, but the firewall and/or router is blocking that port, traffic can't move through it in order to share torrent data.

How to Speed up BitTorrent Clients

Most firewall programs let you choose which ports can be open and closed. Similarly, you can set up port forwarding on a router so that it will accept the traffic through the designated port and then forward those requests to the computer that's running the torrent client.

For BitTorrent, many home users set up port forwarding on the TCP range 6881–6889. These ports must be directed to the computer running the BitTorrent client. If more than one computer on the network might run BitTorrent, a different range like 6890–6899 or 6990–6999 can be used for each. Remember that BitTorrent uses ports in the 6881–6999 range only.

The router, firewall software, and torrent client all have to agree on the port that's used for BitTorrent traffic. This means that even if the router and client software are configured to use the same port, the firewall could still be blocking it and preventing traffic.

Other Factors That Slow Down Torrenting

Some ISPs throttle or even completely block P2P traffic. If your ISP does this, you might consider using an online torrent client like Put.io so that the traffic is seen as regular HTTP traffic, not BitTorrent.

Another way to stop your ISP from blocking P2P traffic is to access the internet through a VPN service that supports torrents.

Your physical or wireless connection might be the problem. If you're downloading torrents from a wireless computer, consider using a wired connection or sitting in a room just next to the wireless router to mitigate any signal degradation.

Low available bandwidth on the network is another possible reason for torrents to upload or download slowly. A limited amount of data can be uploaded and downloaded at any given time, and when the limit is reached, every device using the network experiences slow speeds. The only way around this is for other devices to stop using the network, or for the network to be upgraded to support more bandwidth.

Along those same lines, another tip to download torrents faster is to download only one torrent at a time. When you run several torrent downloads simultaneously, each torrent effectively downloads more slowly than if they were to run individually.

Prioritizing torrents is one way to keep all your downloads running but keep one at the top of the list so that the client reserves enough computer power to download that one first. Most torrent programs support this feature.

If the torrent you're downloading has too little a number of seeders, then there aren't enough sources from which to download the file. Look for the torrent elsewhere with more seeders, or wait for more users to upload the file so that you can download it.

A computer that's slow overall, and therefore also slow at downloading torrents, might be infected with malware or might need some of its running programs shut down to free up system resources.