This week BitTorrent celebrated its 12th anniversary which prompted us to take a detailed look at the current state of the world#s most popular file-sharing landscape. New statistics show that at any given moment about 30 million peers are connected to the top BitTorrent trackers, sharing 4.5 million unique torrent files. Less than 0.0003% of all torrents tracked are shared by more than 1,000 people at once, while the best seeded torrent is an ad.

BitTorrent has come a long way since it was first announced to the public on July 2nd 2003.

During the past decade the protocol has established itself as the dominant file-sharing technology, used on a daily basis by millions of people all across the world.

Due to its decentralized nature it’s difficult to obtain statistics on the number of people who use BitTorrent, but data from the largest public trackers can give a good indication.

The three largest public trackers at the moment are PublicBitTorrent, OpenBittorrent and Istole.it, who all use the beerware-licensed Opentracker software. TorrentFreak asked their operators to provide some statistics on how many torrents they track, and how many people are connected at any given point in time.

The owners all agreed to share their statistics, resulting in a unique snapshot of the BitTorrent ecosystem today.

In the table below we report the number of unique torrents that each of the trackers has listed, as well as the number of peers (downloaders + uploaders) and seeders (uploaders). In addition, the trackers combined their data to arrive at a total that doesn’t include any duplicate peers or hashes.

3 Largest BitTorrent Trackers, July 2013 # Tracker Torrents Peers Seeders torrentfreak.com 1 OpenBitTorrent 4,239,374 26,391,969 21,027,875 2 PublicBitTorrent 4,247,717 23,386,982 18,066,840 3 Istole.it 2,780,298 21,859,219 16,913,149 Total (combined) 4,508,514 29,414,471 22,258,311

As can be seen above, OpenBitTorrent tracks the most peers of the three, more than 26 million at the time of the measurement. PublicBitTorrent tracks a few million less but has more torrents, 4,247,717 to be precise.

Since there is quite a bit of overlap in the peers and torrents we asked the owners to combine their data for the ‘total’ row. To do this the trackers matched their data and picked the largest swarm for every unique torrent. The result is a fairly complete snapshot of the BitTorrent ecosystem, without any duplicate peers.

The combined data shows that the total number of torrents with a unique hash tracked by either tracker is 4,508,514. The total number of peers is 29,414,471, but can vary a few million from day to day. The current snapshot was taken on Tuesday and most peers are usually connected during the weekend.

With the combined data we are also able to look at how the peers are distributed over these 4.5 million torrents.

As can be seen below, BitTorrent has a very long tail where the majority of the torrents have relatively few downloaders. In fact, more than 91% of all torrents have between just 1 and 10 people sharing. Only 1,282 torrents are shared by more than 1,000 people, which is less than 0.0003% of all torrents tracked.

BitTorrent distribution, July 2013 Peers Torrents torrentfreak.com 1-10 4,133,225 10-100 387,534 100-1,000 30,301 1,000-10,000 1,249 10,000-20,000 28 20,000-30,000 4 30,000 1

Finally, we take a look at the best and the worst-seeded torrents connected to these trackers. Perhaps not surprisingly we found that it’s mostly porn torrents that are badly seeded. The torrent with the worst ratio was a “top 40 adult stars collection,” which had 14 seeders and 412 leechers, a ratio of 0.0316.

The credit for the best ratio goes to BitTorrent Inc’s Kaskade promo bundle, which has a ratio of 907.0500 with 18,141 seeders and just 20 leechers.

The torrent with the most seeders of all is “SpeedUpMyComputer” which is promoted through uTorrent via billions of in-app advertisements. This torrent had 27,599 seeders and just 96 leechers.

The above gives a unique insight into the current state of the BitTorrent ecosystem, and we want to thank the trackers for their voluntary cooperation. We hope to repeat this overview on a yearly basis so we can keep track of how it develops over time.